When my son was 18, he chose to leave home, only to ask to move back in at 21. I said no. He was not happy with me at all. Now 29, he has a great job and a baby on the way.
My daughter was a heroin addict and after high school when I realized her problem, I told her to get help or get out. She too, was angry and blamed me for everything, but she left. At one time, I came to peace with the realization that my daughter would probably die from drug abuse. She proved me wrong. She lived and is amazing. My daughter is clean and chose "no drugs" for delivery or recovery during the birth of her child.
I listen to your callers and I want to scream. I knew that saying no was the only way my children would find themselves. And they both did. I know they struggled, suffered and so did I -- silently. They never knew my pain, worry or tears. They pulled themselves out. They got it together. I am so proud of them. Raising kids that are able to succeed is very hard, but you've got to do the RIGHT THING -- even if it hurts -- because the payoff is phenomenal.