As the other parents have said,
you did the right thing. I have an AS. I had to face many of the same issues as you have. Although my journey of recovery doesn't involve being an addict, I know that Being an addict doesn't make you any more powerful or in charge of his addiction.
We have a few " double-dippers" as we call them, people who attend both AA and Al-Anon meetings. there are differences as well as similarities.
Maybe when you feel able in your own recovery you might want to try that.
In the mean time,
There are parents here who are recovering addicts like you who share your journey.
don't be uncomfortable around any of us. Everyone who visits here, is about supporting recovery. there is no judgment here, we all fight our own desire to feel responsible.
I have a thread going where people gave me some great advice for how to "talk" /respond to your addict now that he is out of your home. Its not over. He will call and until he is ready to recover he might get difficult.
Prayers to you and your son:praying