Chicory my dear, I know that being around a loved one, who is an alcoholic is hell, and I also know that wanting to fix them, it, everything is also hell for us, and we have to handle it as best each of us can.
It is your hands, not anyone from SR or anywhere else, and personally I feel you have done a lot to let your son become responsible for his own care and upkeep. That he still has his drink is upsetting for you, but please don't despair at this.
Stick to your boundaries, tell yourself that you need and deserve good in life and take steps to give yourself the attention you require, love him but love yourself also.
It may be a while yet, even a long time before he accepts the need to cease drinking, so til then leave it in God's hands and try to do what you would do for yourself if he were not as he is.
I have you in my prayers.