I left my AH. One of my friends told me the next day that "you might just have done him the biggest favor anyone will ever do him, even if he doesn't see it that way right now."
It's been about five months, and he's still sober -- he checked himself into rehab 24 hours after I left.
I spent four years in Al-Anon before I left. I spent the first few months after leaving feeling like I had gotten everything I needed. And only recently have I seen in myself the fallout of living with an alcoholic for 20 years. Whatever else you do, find an Al-Anon meeting (in real life or online) and work on your own recovery. Because the coping mechanisms we develop living with an alcoholic continue to poison our lives after we leave, if we let them.
I would say to worry less about him and why his sobriety didn't stick, and more about what you can do to heal and get to a point where you can live a rich, meaningful life without dysfunction.
