How do I not let this control my every thought?

[Travis]

Just wondering on some ideas to keep this from dominating everything I do. I found out my wife was having an affair on 03/11. Confronted her. She denied and started bringing up every small thing I've done in the last 11 years. Said she wanted out. We had never even had a discussion of the possibility of us splitting up. I'm sure it's the fact that she was "busted". Well, on 04/11 she said she needed to go to her dad's to have someone to talk to and her and our boys would be back in a few hours. She called later and said they wouldn't be coming home again. This is the short version of it all, but I believe it's over and she's even been taking my boys to her boyfriends and spending the night. She even had the nerve to bring her boyfriend's mother with her to pick up the boys on Mother's Day. It takes two to make it work and she has no desire, so I believe it's really over. My question is, how do I not let these thoughts dominate every minute of every day. The only time I don't think about it is when my kids are here, which is not nearly enough. We're going through all the attorney b.s. right now, so there are a lot of hard feelings. I even e-mailed her last night, since we can't talk about things, and told her no matter what she felt for me, I didn't want the boys to suffer. She wouldn't let my son go to baseball practice, I'm the coach of his team, yesterday. Baseball is his favorite thing in the world right now. I told her we are both parents and would always be their parents and we should come to an understanding about the boys. The e-mail I got back said, "When is a convenient time for me to come get my personal items? I need to know so I can rent a moving truck?" I'm not going to lie down and let her just take everything and dominate all activities with my boys. They are what I'm fighting for and I explained to her in the e-mail that we are going to have several disagreements over the weeks/months/years ahead, but the boys should always come first.
I'm tired of thinking about this all the time. The mental anguish starts to affect me physically (I've lost 23 lbs in 5 weeks and I was maybe only 10 lbs overweight). Please, any advice on how to deal with this all would be greatly appreciated.