He sounds like he might be manic/depressive. I don’t know I’m not a doctor.
I am sorry you are going through this. It is very difficult to make the appropriate choices related to manipulative alcoholics. Possibly the best thing you can do for him is to let him hit rock bottom, then he’ll be forced to pick a path, which will be his choice.
He does seem to be bi-polar/manic-depressive. My youngest fits this bill and sounds much like this guy. Hard to deal with.