Hi, Txbuttercup. Welcome to SR. There is a saying around here and in the AA and Al-Anon rooms: when we know better, we do better.
It sounds like you are teetering between maintaining boundaries--leaving if he drinks--and wanting to help him in his recovery--go to the appointment with him.
As Refiner and others have said, your recovery is yours, his is his.
You can't control another's behavior. He is an addict, alas, and doesn't seem to want to change just now.
You, on the other hand, do. Go with that. Work a plan. Could be moving out. Could be just getting away for a time when he drinks.
Keep going to Al-Anon. It sounds like it is helping you. Don't let him get into that with you.
Should you have let him get arrested? Yah, probably. If nothing else, it would have given you a few days of quiet that would help you figure things out.
And it would have sent him a heckava message. Peace.