It is painful to watch anyone we love self-destruct with drugs, and worse when others enable and laugh as if it's just a party and fun. Drugs kill, drugs destroy families and leaves chaos in the path of anyone who uses.
It's painful but there is nothing you can do to stop the circus and make it leave town.
Venting here is a good way to let off steam. Meetings have helped many of us learn to take care of ourselves and let go of the need to fix someone who doesn't want fixing.
My heart goes out to you, I've been to that circus and was not amused by the clowns.
Hugs