Thanks for responding!
Yes, I'm reading tons of threads. The post that made me sign up was one by the mother of a 22-year-old pot smoker (can't recall her name right off). The advice she received on that thread was so excellent that I've bookmarked the post for quick reference.
We learn what we need to learn, when we need to learn it--IF we want to learn it. And I do. I want to learn how to stop enabling him.
He IS young. I've read that many parents whose children have OD'd wished they had stopped enabling their children sooner.