How do I stop thinking about this 24/7?

I know I'm in a different situation than most going through separation or divorce issues. I'm still living with my wife and she is making an effort. Her effort is more of a wait and see if something improves without any real action or changes on her part... But she's still here. I feel like I'm doing a good job of working on self improvement and that is helping the situation.  What I need to know is how do I stop thinking about my situation every freaking minute of the day? It doesn't help anything. My day starts okay but constant thinking and worrying form doubts over the course of the day. By the end of my work shift I'm almost cruel to myself in the thoughts and scenarios of losing her, imagined future love interests for her, wondering how I can screw this up,  etc. I hide all this pretty well and usually the interaction with her goes well,  but inside I'm crying. I really want to be as confident,  charming, and happy as I'm pretending to be to her. I know that eventually my strength will suffer in trying to maintain this without true improvement internally. 
 
I think I need to find a friend or hobby or something I can enjoy that has nothing to do with her. Problem is there is no time in my day for that. Ideas?