I suggest you seek out two support groups:

Al-Anon - this is a support group for family and friends of alcholics
Mood Disorders Support Group - this isn't just about him, this is about your own mental health too. He may een eventually attend with you.

As hard as this is, I say draw the line. This is affecting both you and the children. I would ask him to part for a while until such time as he is either showing improvement or demonstrating he is seeking and following a treatment plan.