Please don't judge me for what i'm about to say, I know you feel like crap now (and I haven't been drinking btw), so my intent isn't to make you feel worse, it's just to possibly show you that he could have had other reasons for not sticking with you. Remember what I said a while back in another thread about guys and "strange", and their desire to spread their seed around? I've known MANY guys who used whatever lame reasonings to tell chicks they don't want to be with them anymore. To me (and I don't know crap other than knowing guys REAL well, so this might not be his reason), he knew a very good excuse reason of not bein able to have kids and whatever else CF wise, and used that. If this was a bet, and god could tell us his real reasons, I'd bet everything I own that he said that because he didn't want to be tied down to one woman anymore. I'm not saying he didn't love you, but guys are very freaky when it comes to thinking "this is it, for the rest of my life" mate wise. Women can be very cool with that idea, but most men find it horrifying. And that has ZERO to do with how cool of a chick your chick is, as in smarts, beauty, body, all kinds of stuff.
The guys who are smart, mature, and actually understand that there is no "magic booty" out there (took me a while to figure that out) are the types that can settle down with one woman and it doesn't scare them to death. I was a manwhore growing up, so I got my "oats" out of my system. I'll still look at fine women here and there, and wonder how fun that might be, but it's not worth destroying what i have now, and i've come to grips with growing old with this woman and dying together. It took me a long time to fully accept that (before I was with her), and MANY temptations of the flesh have confronted me, but i've always been a "good guy" and didn't stray. I suppose one of the reasons I feel so strong about not cheating is because #1 I wouldn't want it done to me and having my world come crashing down, and #2 My dad did it to my mom and ruined her life and our lives in the process. You gotta be a bigger man, than the little man (love that saying).
This is a tremendous defect in males given modern day rules regarding relationships in general. But in the big scheme of things one of us had to be selected to be this way to ensure the survival and thriving of our species. It sucks it's still with us though, because theres enough people here now. We don't need this very strong urge driving us anymore.
Anyways, don't take my opinion for anything deeper than just a "maybe it was this". You did nothing wrong, and i'm not saying the situation WAS what I described. Just look at it like he is the crappy person, regardless why he made that decision.