Very tough. I have a liquor problem. Can't stop when I start. My wife is caring and supportive. Initially her concern annoyed me. I told her to just avoid me when I was in drinking mode. This is not possible. Then I told her to just be supportive and kind. She was. It didn't stop the drinking. It's a cliche, but it has to come from within. The person has to reach a point I think where they themselves realise that enough is enough. Unfortunately, on the way we impact other lives. I think maybe you can consider encouraging him in indirect ways. Not telling him to stop or cut down. But showing how much fun you can have when sober. I can only imagine what kind of a challenge this is. My wife was there for me and supportive and encouraged fun that did not involve drinking. It helped. Good luck.