it sucks sorry to hear about your break-up, The best thing to do now is get busy hit the gym, learn how to play the guitar, hang out with the boys, go make a movie, do something that you have alwas wanted to try, skyjumping?
and exersise some more, it really helps with the over thinking.
Finally read this and follow it, it will help:
http://www.loveshack.org/forums/t81399/