i took baby steps, too. seemed less horrible to ease out. i'm still workin on it.
bolina asked about the payoff. this is a terrific thing to remember. it sometimes takes some soul-searching.
from where i am, it looks like you get sucked in by his mental illness distresses. this is a tricky one, because they can say, we can say, even get a dr to say, that he has an illness. even if you buy into the "born with it" model, there is still a lot one can do to offset the debilitating effects of depression. i think we can be sympathetic to a degree, then the "what are you doing to recognize the patterns, and fight the depression?"
it can be treatable.
but, again, probably not if he is drinking.
i finally decided that my xabf has this image of himself as a complete and utter screw-up, and he feels sorry for himself much of the time. i think it's his way of not dealing.
don't have to put too much pressure on yourself to have all the answers right now. you took a long time to get in this difficult situation after all.