Paula, your thoughts seem pretty much on the mark even thought that's not how you'd like this to turn out.
Hello-kitty said what was on my mind too, as sad as this is, it's his choice to make, even if it is a bad choice.
How easy that is to say and how hard that was for me to accept when it was my son.
Meetings saved my life, maybe check your area and try some Al-anon, Nar-Anon or CoDA meetings and see if they don't help you too.
Hugs