Having been just such a son; demand he be the man you know he can be tell him how such a man behaves.
If you have examples to point to in your family point them out.
I assume he knows about AA and you’ve suggested counseling.
He can and will heal.
He and only he can choose.
Prepare that he may not now or ever.
The choice must be his. Sometimes it has to get really, really, really bad. Sometimes one never chooses.
Model and show what ferocious other directed love looks like: what is best for him not easiest for us.
He is young and not yet lost. The prognosis is good.
I was far, far, more gone and with my mother’s love and the support of thousands of unnamed people, I’m still here.
Your son will make it.
Take care of yourself you can not pour from an empty cup.
May grace hold you both through the storm.
My parents put me in rehab (the first time) at 14. After attempts at sobriety over 3 decades, I am sober (as you know as I have said it probably too many times). My mother told me, "As long as you were alive, I had hope." That was powerful to me. My brother, completely stopped talking to me and told my mother to tell me he would not talk to me until I quit using. After I quit 12/16/17, I was working through the steps of AA. I got to steps 6 & 7 and started making amends. My brother told me that he had always waited on the phone call from my parents or my partner (that died from this dis-ease) that I was dead. That was also powerful and really hit me in the soul regarding how my addiction had affected those that cared for me the most. Yes, you must take care of yourself. It is a natural law that if you change, everyone around you changes. That is not to put the responsibility on you regarding anyone else's issue...it is just the way the Universe seems to work.