Sorry to hear but sounds like it's for the better. In my opinion, when someone has needed to attend AA at some point out of necessity, although they may not ever drink again, the issues that perhaps caused them to drink to excess in the first place might "go into hiding" for a bit, but might not ever go away. Sounds like that's possibly the case here. It likely has little to nothing to do with you, at all. And not to generalize, as I have some extremely close friends that are artists---but they all seem to be somewhat damaged as a general rule. Although at the same time, some of the most kind, sensitive, and aware people you'll find. Artists in general, I mean. So to me, I think there are perhaps some things going on in his mind that he can't control, and it's possible that the relationship, ANY relationship at that, magnify them to the point he needed to pull away and go back into his own head alone. Just my opinion, hang tough--