Stands, may I suggest the book 'Don't Let Your Kids Kill You' by Charles Rubin? It's available on amazon if it isn't in your local bookstore. It focuses solely on parents and makes some very important points. The author has two children, both of whom have been drug addicts for years; one has gotten clean but didn't until he was totally on his own. Rubin tells of the years he spent taking responsibility, blaming himself, and second-guessing everything he'd ever done as a parent; he tells how his obsession with his sons' addictions wrecked his marriage, and how, finally, he began to pick up his own life again.
We can't make choices for our addicted kids; only they can. We can't control them. We can't try to mold them or our families to meet our expectations. They are individuals who are going to live their lives. We are also individuals who need to live our own lives.
My husband is finding this book helpful right now.