I'm also mom to a 23 year old alcoholic. My son is now almost 8 months sober, but we've had some hellish times to get to this point. I think the addict/alcoholic figure out where we are most vulnerable and strike us there when they are in desperate straights. Fortunately, for me, my DS wasn't a mean drunk. He mostly just isolated himself in his room and was drinking himself to death. We were fairly good about not enabling- however, for a long time we provided a roof over his head because having him live homeless on the streets was extremely difficult for his Dad and me --- and he knew it.
I think I'm fortunate that there wasn't anything in his uprbinging that I felt guilty about or that he could use to try and manipulate us further than he already was. Like your DS, my son had a great life filled with many opportunities. Unfortunately, they were born with the genetic predisposition to be addicts.
While drinking my DS appeared to have so many problems (underemployed, not driving, socially isolating, depressed)- its amazing how stopping drinking has fixed most of his problems.
Let your DS hit bottom and figure out how to take care of himself. It wasn't until my DS was truly out of options, that he finally realized that he did not want to continue to live that way. He's now sober, working full time, taking college courses, driving, and experiencing life. So, don't give up hope but just know there is NOTHING that you can do that make your son want to get sober. Well, there is one thing that might help- don't make it easier for him to live the life of an alcoholic.
Remember that you didn't cause your son to become an alcoholic and can't change or cure him. You can only change yourself and it sounds like you are on your way to taking care of you and finding your serenity. Hang around and you'll get so much from this board.