I know how it feels, the heart vs. the mind but the good news is that he recognizes he needs help and seems to want to stop so he is trying to get back on his feet. The relapse issue isn't in your control.
But maintaining his recovery is key to any potential for success in a relationship. As much as I love the RABF, I would want to see sustained recovery (and productive, working, going to meetings etc) before even thinking about taking it to the next level.
The heart, however, is harder to convince when it comes to slowing down. I may eat my words .. I'll post on SR about how I am moving in with the RABF and they will throw rotten fruit at me --- If they don't I hope they will! Because there is NO hurry to go down that path until he proves to me that he can maintain sobriety.
I am really trying also to focus on myself and my life as he works on his recovery and honestly, it makes our relationship stronger. Hang in there, it gets easier!