I hear you about dealing with slips in the past. Has he ever been as comitted as he seems now? Acting likes there's no tomorrow is the just for today I won't use. As much as you want to help him get through this he HAS to do it himself.
He's doing all the right things and from what you've posted he's doing it for him AND you. Maybe MAYBE you two should not spend time together for a few weeks. I'm not saying no contact but limited. He has to focus on his recovery. He'll have nothing without it.
Once again you need to do what's best any healthy for you.
Me:40 W: 39 T: 17 years M: 15 years S-9 D-6 D final 11/10/2009
"We are all faced with a series of great opportunities brilliantly disguised as insoluble problems."