You didn't cause it.
You can't control it.
You can't cure it.
You are not at fault. You are not responsible. He is walking his own path.
My AH had all sorts of excuses for drinking, none of which had to do with me or reality. "I drink because of your damn horses" was one. Or, "I drink because I'm under a lot of stress to provide for this family" was another. The best one was "I drink because I'm worried about money and how we'll make ends meet!" This excuse was spoken many times in the same year he pulled down over a million dollars in income.
He drinks because he drinks. A hot, skinny wife, cute kids, a great house and good health cannot make him want to stop. Only he can do this for himself.