I have no regrets even though I don't have the household income, and the family home had to be sold, and I can't look forward to a share of exH's pension in my old age -- there are lots of financial downsides but I decided that the emotional toll on me was too high a cost to pay. Above all, the soul destroying effects of trying to be married to someone who basically didn't want to have sex with you was too much of a price for me to pay. At least the problems I had when it all finally screeched to a halt were things I could do something about. To cut a long story short, we are settled, and we are happy, as much as I think we could be.
Long story:
My mind got over the need to find proof after a stretch of horrible doubt and uncertainty. That was a period of real torment because I take marriage seriously, but above all I knew there would be huge repercussions for the children in every way imaginable (but I had to also look at the repercussions for them of us staying together -- see next paragraph).
He was and remains a narcissist and living under the same roof as him was almost impossible most of the time. He was a terrible co-parent while we were married, and a textbook abusive husband. Even without finding any of the gay porn that I came across I frequently considered ending it, and I think my regrets centre around not having done that because it was misery for the children, and then finding the porn knocked me flat, emotionally speaking, for so long I again wasted years before being able to get going again. (I wasn't on MN back then.) I had stayed in hopes of improving the relationship, somehow managing to 'get it right'. I kicked myself so hard when I realised what the real problem probably was. I now consider the discovery a gift to me from whatever god is out there.
We have a very detailed co-parenting agreement that I hoped would be a guarantee of smooth sailing for me, but he has found room in it to find fault with me, to dispute my interpretation (supplemented by notes I took and memories I have of our mediation sessions) of passages. He is a lawyer and he thinks it is no skin off his nose (and it doesn't cost him a penny) to haul me back to post divorce court on contempt of court charges which I have had to defend by myself. It has been very quiet on that front for a while now but I was in court maybe four times since 2010, with no good result for exH.
I think it takes a remarkably selfish personality to use someone else as their front. No matter how difficult it may be to carry a social stigma, nobody owes you a good public image or a domestic arrangement where your meals are served to you, your bathroom is cleaned, and your laundry done, with the odd nod to sex from time to time if you feel like it with no thought given to what your partner's hopes for marriage might have been. Asking someone to marry you without telling them that one important detail about yourself takes away the fiancee's right to make an informed decision about the rest of her life, and that is selfish and cruel -- and the theft of options you might otherwise have chosen.
Imo bringing children into it, effectively saddling them with the job of helping you look straight, from birth, is cruel above all to the children. My 5 DCs have coped well with the tough changes in their lives. Luckily we had never enjoyed an affluent lifestyle so having less money didn't really hit them. We live quite simply and I shop where I always shopped (Aldi, etc) and we still go looking at the sale or final clearance rack whenever we go out to buy clothes. They have all managed to find babysitting or handyman/gardening jobs for themselves in turn, just as the oldest was already doing pre-split. They had a good supportive school on which I leaned when it became clear that we were going to divorce (exH told the DCs in the car on the way to school one morning and I went as soon as he told me this, cried on the Head's shoulder, and brought them home). I asked one particular teacher, the art lady whom they had all known since they were tiny, if she would be there for them if they wanted to talk to a third party about it all and she agreed. Oldest DD had moved on to secondary and when I broke the news to her she told me she had come across gay stuff on the computer herself 
. She had carried that around with her for quite a while 
.
Apart from my one DS, their academic life didn't suffer. DS was already having difficulties though, even before we separated. What made a difference to him was getting away from it all to university where he has really come into his own. I think DS may have guessed what was up with exH, or maybe there were whispers among his football team exH used to participate in 5Ks and trained around town in a pair of extremely white and tight running shorts that behaved like a wet white t-shirt once he had sweated a bit. You could see people's heads turn as he ran past. Then there were his everyday clothes and shoes, which tended to be on the 'dandy' side. Plus there was exH's controlling personality and tendency to fixate on the glass half empty he always needed something or someone to criticise to death, which DS hated. The girls have all continued along a high achieving trajectory. All the DCs have been blessed with lovely friends, something I really appreciate especially for DS, who has seen how healthy families and healthy relationships operate thanks to the parents of his friends. I have no brothers and we live a long way from any of my family anyway. In turn, the DCs have all stopped having anything to do with him as they have turned 18 and are no longer obliged to. His loss.