I am not familiar enough with your sitch but I always think that "It's not you, it's me" really means something like, "It's a little bit you but mostly me." Know what I mean? That is why the book Passionate Marriage talks so much about "holding on to yourself" in the midst of R conflict. It is always somewhat about each party.
Glad your H is making noises about wanting to change. What does that mean to him exactly? I have gone many rounds of that with my H. I dont' think it is that my H purposely didn't step up to the plate but he was placating me with no actual plan for change AND a million excuses why change is impossible.
