Welcome! Sorry you are in the midst of all this.
If I were in your shoes, I would start educating myself on alcoholism and learn how I am enabling his drinking, how I can stop enabling him and help myself deal with it all. Have you tried AlAnon?
If it were me, I would give him a definite deadline to move out. Obviously he finds it easy to ignore the fact that he owes you rent because he has learned he can safely do so. He has no motivation to change that since its to his advantage to continue to use you. So tell him he has 30 days to find another place. Period. And if he doesn't, dump his stuff on the front lawn and change the locks. Treat him as you would any other tenant who is not paying their rent. He can only use you as long as you choose to let him.