I agree with Red Panda. You can't fix him. Just trying to will make him more angry, as you've already seen.

He needs to deal with his substance abuse problem first, before any other problems can be addressed. Too much alcohol can cause all the behaviors you've seen. He's never been diagnosed as bipolar, but he does have an alcohol problem. Once he's gone through a detox, then any other problems he may have can be assessed by a psychiatrist and dealt with. Alcohol has to go first, then whatever problems he has when that's dealt with. But HE has to want to go to AA or detox, and he doesn't seem to be ready to go yet. You can't do it for him.

You're trying to be a good friend, but he's not receptive now. I'd leave him alone for awhile.