This reminds me of a similar situation I was in. My guy did change his behaviour quite a lot (it took about a year), stopped feeling sorry for himself and realised how he had treated me. But being in such horrible emotionally draining situation for two years I never felt the same way as I did in the beginning so realised last month that I had to break up with him.
Its good he is getting help but I feel the best option is for you is to give him some time to really develop and work on himself without you. he needs to go through this alone. And you need to spend some time on your own to figure out whats best for you and be sure of whether you truly want to be with him or not. Its understandable that you still care a lot for him but you just have to think about you and whats best for you.
I am finding it hard to cope without him but deep down I know its for the best