I'll respond as an alcoholic in recovery: refusing to get help is just another way of not quitting. My best thinking got me drunk, it was only when I went to AA in 1991 and took suggestions that, one day at a time, I didn't drink. He can delude himself but you don't have to be. And as a codependent I know there's nothing you can say or do that will affect his drinking in any way.
So you must save yourself. Alanon was a lifesaver for me and I recommend it.