I understand completely how you feel. It's hard to have that person that you have shared your most intimate moments with, those little inside jokes, glances, and everything else with for so long not there for those things.
It's at times like these that you may need to find something to distract you from those thoughts and feelings so you don't break down and try to contact her. For me, if I'm not at work, then I do something fun with the kids. If they are asleep, then I work on my personal projects or find a game to play that helps me be involved. Heck, even a movie will do in a pinch.
Just know that as time goes on, it will become easier as you let go of that and work toward doing things to better yourself.
M:35 W:31 S: 9 D: 5 M: 11.5 yrs BD: 5/13 W moved out: 7/13