Just echoing Vaps words. You have to find something to occupy your mind. Wondering where she is or who she is with is pointless. I wish I could remember exactly how I overcame that, but I can't and it was never a real issue for me. I guess I realized that OM (if there was an OM, I assume so) was not the real issue. I also realized that I had zero control over it. I focused on trying to figure out my flaws instead and ways I could improve.
Vise, for the separation I think you just have to accept that it is coming. I thought things were going to be a lot worse for me once that happened, but it was actually better than living in the same house under those conditions. I think one important thing is to make your wife feel exactly what it will be like without you. For me, if/when we get divorced, then that is it, no more friendship, in fact, I would not be able to talk to her again. I want to make sure she feels what it will be like without me. She can work through her issues on her own since I do not interfere in anyway. I have seen movement lately though I am not sure where it will lead, but things have changed. The best part is that I have become detached enough where I am 100% fine with any outcome. I know for a fact I will be fine on my own... 9 months ago though I wasn't so sure.