(((WW))) I could have written your post.
You did the right thing... he has to face himself to fix himself. We (and I mean me, too) cannot continue to provide that soft landing... that softer, gentler way.
Addiction is harsh and it takes pain to build the strength needed to fight it.
If you aren't attending face to face meetings, I would suggest you consider starting now. If you are attending, double or triple up. This is a hard time, but you can do this, Wascally. My kids were no more prepared than yours, but far younger... and they did do this.
I guess you have to believe in your son and in his Higher Power. They can fight his addiction.
Saying this with all the love I can muster, I think Our job is to fight ours.