Based on your description, he sounds like an alcoholic to me. But he has to make that determination for himself. Talking to other alcoholics can help. As a non-alcoholic you will never really be able to understand his drinking. But I do. Other alcoholics do. We have all had similar experiences, and we have all been through a kind of hell.
Is there anywhere around there that he can go to talk with other alcoholics? Has he ever talked about going to an AA meeting? If he does, encourage it.
He may decide he wants what the recovering alcoholics have. That would be a very good thing.