plenty more fish in the sea honey, shit at the minute, but get it out of your system and get laid honey, forget her, if she's going to keep buggering off to the ex, don't have her back unless you don't mind sharing.
BC is right, there are a lot of nice people at the Playground Boards, take the edge of the loss.
I know what you are going through as I have experience it on a few occaisions myself. Do things that require concentration that will keep your ex out of your thoughts......sort of break the obsessive thought pattern to allow your healing to begin....
my first break up I could not eat, I could not sleep for 72 hours straight......Yikes! I do not want to go there again.
Hang in there my friend.