Jemin/sis - Sorry, have been at work this morning, but I've cut and pasted that post, but have adapted it a little for your situation, as it was originally for another poster - shows you how common this is - in fact there is another thread at the moment about this very practice:
Try to "timeline" when you first started feeling unsettled - or last felt genuine joy. It will really help your understanding of what has been happening to you in recent times.
People about to embark on an affair engage in a practice which I had never heard about before, but since joining Mumsnet, I have seen it over and over again. They start to withdraw from the marriage, to create a "gap" to allow the affair to happen. My H had been in contact with OW for about 10 months before he actually agreed to have an affair with her. It's all part of the justification process, so that when they finally do start a proper affair, they've managed to reduce their marriage from what it once was.
Although we'd had ups and downs over 24 years, we were actually in a very loving "up" phase just before OW got in contact. In fact, the last time I remember feeling genuine happiness was exactly the month before OW sent an E mail to him at work...
The basic details of my H's affair are that at a time when he was feeling old, grey, overweight and very unhappy at work, a former colleague, who had made it very clear years earlier that she wanted an affair with him, got in touch via work E mail. By this time, she was married herself and was purporting to be very happy. He wouldn't have dreamt of telling me about these E mails, because of this woman's previous (unsuccessful) efforts - he thought it would create a very difficult conversation with me (and boy, did he hate those) and of course, he completely deluded himself that this was harmless.
A fairly innocent exchange of E mails took place over a few months, during which time she reminded H of how handsome and gorgeous everyone had always thought he was, how dynamic and popular etc etc. This must have been like nectar to my H at the time - and I can absolutely understand how addictive this was. I've had to be honest myself here and admit that had someone come along like that for me at certain times in my life, I might well have encouraged it.
Gradually, barriers got broken down though - the move to texting - repeated requests from her to meet up, met with very wishy-washy refusals from him that meant she would ask again. It took her 10 months in all to persuade him to meet and by then, he had managed to create the gap necessary in what had always been a very loving marriage.
I have E mails from around the start of that 10 month pre-affair period and I was saying to friends then that I was feeling unsettled and unhappy, but couldn't put my finger on why this was. On the face of it, everything was pretty good, especially my business, which was in a real "up phase". I put it down to autumn blues, a bit of a career crisis (business was great but I wasn't really enjoying work any more), worry about secondary school choices etc. - but absolutely not my relationship with my H.
His withdrawal was pretty subtle, you see.
Always a lazy and untidy man, he became even lazier - and previously when I had pointed this out, he would apologise, agree he hadn't done as much as he should have done etc. But around this time, he started to get very defensive when challenged about how come the house was a tip when he'd been off all day and I'd been at work. I remember several times, asking how come I was the bad guy here?
There were other little things - in general, he is an earlier riser than me - and on hearing me get up, he would always put the kettle on and bring up a cup of tea. That stopped. I know these sound like little things - and they are reasonably subtle, so wouldn't necessarily register.
If off for a few days or at weekends, apart from getting very little done, preferring to spend hours on the PC or asleep on the sofa, he wouldn't shave - or some days, even shower. Then, after behaving like a lazy oaf all day and looking awful, he would ask to make love and sound disappointed when I didn't want to. He recognises now that all this was pretty manipulative behaviour...and quite obviously I wouldn't have wanted sex with him after a day like that!
What also complicated this situation in our case was that he was feeling very, very depressed at work. He'd had 2 really big setbacks close together and hated the job he was doing. He could see no end in sight and he was very, very down. We recall now that I was extremely supportive of him at this time and we talked a lot about how he could improve his lot. I felt very sorry for him and admired him for getting on with it and not taking sick leave. The reason I'm saying all this is because at least some of his behaviour could be attributed to feeling so down about work...
During the "active phase" of his affair (4 months in total), this withdrawal became much more overt - his behaviour at home was actually appalling, hence me confronting him in the end. He seemed stressed all the time, got disproportionately angry about the slightest thing, picked fault in everything and everyone and withdrew more and more from family life. We always eat together as a family - and mealtimes became a regular battleground, with him getting angry at the kids' table manners, or alternatively, he would "tune out" of conversations and stare into space.
He didn't want sex as frequently - and frankly I had no desire whatsoever to sleep with this angry, lazy man.
At this time, our lives were incredibly busy and I was so caught up in the daily grind of raising the children and running my business that I didn't spend much time pondering what was happening to him.
But there were some real clues, looking back - and often these clues were about how I was feeling. My H only met up with OW twice (she lived miles away) and during the week he met her for the first time, I felt something I recognised even then, as acute stress. I was however preparing for a fairly significant business event and so naturally, I was preoccupied and fretting about it, but I actually remember saying to a friend that I thought the stress I was feeling was disproportionate. I remember having to drive the children that week to a couple of unfamiliar places and taking extra care driving, because I felt so disorientated and almost "out of body". Again though, I put it down to work stress and trying to keep the family show on the road.
This also happened a couple of months later, and the day he met her for the second and final time, I had a terrible day - shouting at the children and just feeling generally awful. I've never suffered from PMT, but it was like others describe it! This time, there was no huge work stress going on - and I couldn't understand it.
About 7 weeks before I found out, we were having lunch one day, when he commented that I was eating noisily. I'd once seen a play when an adulterous man had made the same comment to his wife and a lightbulb went on.
A week later, he was behaving in a particularly arsey fashion and so that night, I sat him down and confronted him about his behaviour and also why he "just wasn't into me at the moment." His eyes welled up with tears and he agreed he was behaving badly. I asked him was he having an affair - and he laughed at the very suggestion. I've got to say at that point, I too wondered who on earth would have an affair with him, looking the way he did.
He told me how much he adored me, how I had always been the love of his life and always would. He attributed all the awful behaviour to feeling very depressed and stressed at work and agreed to visit our GP if this did not improve.
It didn't - the anger carried on more or less as normal, but he had by that time stopped finding fault with everything I did.
About 2 weeks before I found out, he was monumentally insensitive about a business setback I had endured (unfortunately for me, throughout the affair, my business suffered one setback after another) and at that point, I remember thinking that he wasn't the man for me any longer.
In summary, the "distancing" is something people do when they are trying to find the justification for an affair. Knowing him as I do, I'm not in the least surprised that it took him 10 months to give himself permission. He'd never done anything like this before, had always thought that he loved me more than I loved him and we had enjoyed a very happy and loving marriage. He says now and I believe him - if OW had E mailed him and quickly suggested no strings sex, he would have run a mile. His needs in this situation really weren't about sex primarily - and were more about needing to feel adored and special at a time when he felt old, tired and out of potential. Plus, he found the sex with OW very dissatisfying and although he cared about her feelings, her personality and behaviour had started to grate terribly - he started to realise that she was not a nice person at all and found some of her attitudes and beliefs abhorrent to his own values.
The awful behaviour and the stress he endured while the affair was ongoing was because unlike a lot of people, he was rubbish at "compartmentalising" the affair. He actually hated feeling like such a shit and the OW started making lots of demands and behaving with increasing volatility. He looks back on that time now and says he has no happy memories whatsoever - he felt awful about what he had done, but because the OW was still telling him how wonderful he was, it was still pretty addictive.
Fortunately for us, he didn't fall in love with OW and although it has often been hard for me to accept this, he never stopped loving me. By the time I found out, he was trying everything to end it with OW, while allowing her to preserve some dignity. He was scared that if he ended it, there would be a backlash, but he also accepts too that he was such a moral coward in those days, it was much easier for him if she "sacked" him, so he kept refusing to meet up again and urged her to re-commit to her H. On discovery, he gave her up instantly and unequivocally, telling her that he wanted no contact with her ever again. He did try to do this kindly, but realised by this time that he needed to be final.
Since then, we have rebuilt our marriage and learned so much more about eachother than we had in the previous 24 years. It's taught me that good people do have affairs and that at a certain time of life (like the BIL in this case) people are especially vulnerable and in need of escape from life. That affairs happen to good marriages too - it so often isn't because anything was wrong with the primary relationship - apart from familiarity and the boredom that often assails long marriages.
All my H's worst faults throughout our marriage - selfishness, laziness and emotional retardation have vanished. He underwent counselling and this helped enormously. I can honestly say that he is the husband I always dreamed of, and I love him very much. I have also changed - I am no longer complacent, I put our marriage first all the time (within certain boundaries), knowing that our children will be happiest within a secure, loving marriage.
I also worry far less about rubbish - the housework or some minor business problem. This gives you a hell of a perspective.
If your marriage is worth fighting for and love is still there, go for it. But don't, please don't sacrifice your self for it. When you are in "fight" mode like Jem's sister, your dignity is terribly important - and can only be suppressed for so long without causing long-term damage to your esteem. I realise that my case was very different from the point of discovery, but I am old enough and wise enough now to know myself - and I have a far greater duty to myself than my marriage.