Sean,
I agree with the previous poster. Only you know when you have had enough.
My (soon to be ex) AH is devastated that I am pursuing a divorce despite the fact that he has been sober for close to four months. He says, "if you had left me ten years ago, I would have gotten sober then." That tells me he's still not taking responsibility for his actions: It's my fault he didn't get sober earlier.
I lived for close to 20 years with an active alcoholic. I spent the last 5 years in Al-Anon. It made it possible for me to stay somewhat sane while living with an active alcoholic. Starting my recovery in Al-Anon meant that when the breaking point came, I had no doubt. I have no doubt. Nothing he can do or say would make me consider trying again. And that's the point I had to get to before I was willing to leave.
I don't have a broken heart. My heart broke many, many years ago. The only thing that bothers me is that I didn't leave years ago.
Lots of love to you. It's a hard road to travel. Whether you stay or leave.