So it's kind of a shame that you didn't get what you wanted from your affair. It seems like the whole point of doing that, of gambling on an outside relationship is to feel better and to feel something that you're not getting in your other relationships.
But it sounds as though you got left with just blame and guilt and that's not good. My impression is that the guy you chose was just not a good partner, that he was way too caught up in his own dramas and issues. He obviouosly couldn't give you his whole emotional or physical presence and in my opinion, that's just not good enough for any relationship, affair or not. Maybe, if you ever decide to try that again, you'll look for someone who's more together and won't drag you down to his level instead of giving you a lift up like you wanted.
I've got more comments but I'm very short of time right now. I'll come bak later and fill in the blanks.