2ismore and joelybear I am so sorry to read about what has happened to you 
October 2009 my xh told me he didnt love me, there was no chance etc. It wasnt quite so much of a shock for me because I had sensed his unhappiness for a long time and he had said a few things but I chose to bury my head in the sand for a number of reasons. We were together 17 years with 2 dc and I loved him in spite of everything and didnt want my dc in a split family either.
He moved into a rented house on Boxing Day that year thrown out by me due to an ow coming into the mix. Her coming into things made everything so much more painful although she wasnt the cause of our marriage ending apart from maybe giving xh the guts to actually leave.
Those months he was in the house were for me actually helpful because the scales began to fall from my eyes about how he treated me and how actually there were so many changes in him from the man I spent the first years with and not for the better.
I had hoped he would go away and come back to me a changed man, over his blatant MLC,and in the first month or so after went I clung to that even though in my heart I knew it was over and he was too far gone to change. I am a SAHM so did all my crying while the dc were at school and also discovered what a wonderful support network of family and friends I had.
It took me 3 months of real pain to begin to start moving on although on the surface I was fine.
The next 3 months were strangely wonderful because I realised 100% how much he really hadnt loved me and I had been trying so hard for years to get his attention , make him love me , be the wife he wanted. In that time I totally lost track of myself and its a cliche but truly at 44 rediscovering the old me has been wonderful.
The last 6 months of last year were a real rollercoaster with lots of positive stuff eg taking the dc on holiday by myself which I had been worried about. Also lots of heartbreak most of which came from having to get used to my dc being involved with ow and her children and that has really only just stopped hurting very recently.
Now though I am in the process of moving from our family home which yes is sad but I see it as a new start for me. We are divorcing and have already signed off all finance/dc stuff amicably.
My dc are fine and apart from a few tears in the early days I have been astonished at how well they cope. Everyone who knew xh was moving out said to me how resilient dc are and I wouldnt hear it but actually they are. Saying that I have worked really really hard to make it happen - no bad mouthing xh or ow , smiling at news of them and what they had been doing which at times was agony when it involved ow. From day one the dc went to stay with xh one night a week and every other weekend and he never messes us about which I think helps their stability enormously.
I found MN last summer and read so often how its better for dc to have positive parental role models and be living in a happy house. I suppose only time will tell but I think its probably true.
Certainly for me now I am a far happier, more relaxed and emotionally stable person than I was. Yes there is still the odd bad day but then there were far more when I was married. Sometimes the feelings of rejection hit me , the Why Didnt He Love Me refrain in my head starts up. In time though it honestly does get less and less and actually although to begin with I thought he had taken my future away the fact is by leaving he gave it back to me.
On a practical level 2ismore I would just take each day as it comes, get as much from the counselling as you can and I think you will know when you want him to move out. Be kind to yourself and dont feel guilty about junk food /loads of TV etc for the kids its about surviving. Also allow yourself to grieve and dont try to be fine and ok , much better to go with the process and let it out imo.
Everybodys story is different but I hope you can take some solace that in 14 months I have gone from heartbroken to thriving and you can too even though it may not feel like it now