Thank you all so much. All the stuff I've been thinking and contemplating lately has been confirmed and validated by your responses. It's nice to know I'm not alone. It's difficult to hear the truth, but I came here because I wanted to get advice from outside people looking in.
To answer a question that seems to be arising a lot (and at the risk of sounding like a selfish b****) No, I cannot accept him and take him 100% for what he is now. I am not a perfectionist, but the negative attributes (although there are a lot of positive ones too) are too much for me to handle. We've been fighting a lot lately about this stuff and I do not want a future with someone who possesses some of the qualities (self-loathing, negativity, lack of communication skills) that he can't seem to let go of. It's almost like a cycle he can't (or won't) break. He acts this way because it's all he knows, and staying in the same bad habits is easier than dealing with his issues. I'm just confused because he worked so hard to get and stay sober, why wouldn't he try to work on these other things too? He has a second chance at life and isn't even embracing it or living it to the fullest. Again, easy for me to say because I have never been in this situation.
I now see (even clearer) that we did move too fast. I am partially to blame and might always regret that. But these issues would have come up eventually either way. I do think we both put our best feet forward and, even though he was honest about his past right away, I didn't realize how much baggage came with it. And what's bothering me most now is wondering if he even wants to change or if he would be doing it just for me, and if he's even capable at all. Maybe I'm asking too much and he needs someone who won't have such high demands.
He does have a chemical imbalance and takes medicine for it, so I think that he needs to utilize the steps he's learning at his meetings more, get a sponsor again, and talk to a counselor. But, again, I don't know if he's willing, and he doubts if he's capable. I will always care about him (especially since he's my best friend's cousin and I am very close with their whole family) but I don't think this relationship is the best for either of us. At least not right now.
I feel like it's a lose lose either way. If I leave I'm going to miss him like crazy and feel like I gave up or wasn't willing to try hard enough. I'm always going to worry about him. But if I stay I might be setting myself up for disappointment and always get let down. I also risk putting my life on hold and losing myself while trying to fix him. Now I have to find a way to tell him all this...
Thanks again everyone. I'm really happy I came here, although I am feeling really sad and lost right now. Any further advice as to where to go from here would be great.