You have been living with an active alcoholic all this time. You likely won't be able to tell until it's worse, he's managed to keep it hidden all this time.
This is exactly what AlAnon IS good for, and it IS the right place to work it out. This is the struggle many people have dealt with, there could be alot of wisdom and experience in those meetings. There are many times in my meetings when someone shares a specific issue or concern they're grappling with. Other shares may feed on that one, or people approach after the meeting to talk one on one.