I just wanted to throw in here that I had a crazy boyfriend once, maybe not quite as crazy as yours, but he was pretty damn crazy. Anyway, it took me about a year to stop thinking about him everyday, and another two years to stop thinking about him often, like once a week or so. It's now been about 7 years and I hardly ever think of him. When I do, I just laugh. Laugh at what a moron he was. It's not all funny, I learned some valuable life lessons through that relationship, and I believe I grew as a result of it. But, I'm just trying to say, it will eventually reach that point where it's not painful anymore, just something that happened once and, like kitten16 said, a part of who you are now.

Sometimes I like to fantasize about the wreck his life probably is by now and compare to how far I've come...

Oh, also, I kept going back to him even though I know I shouldn't. It's not an uncommon thing to do so don't beat yourself up over trying to be friends with the guy.