*blink blink*
Ooookay... interesting one, Rep!
Quiet, my best friend *caught* his wife with someone else about 9 months ago. Now he's with a gal who treats him like gold but he still thinks about the ex-hahahaha almost daily, missing her.
It'll just take some time. In the meanwhile, go as slow as you need to and try to enjoy the good things you find in this new girl and the fun you have with her. Actually, lots of the advice in this thread is pretty much on-target, lots of different things to try.
Best of luck that it passes soon and not too painfully.