Hugs and prayers for strength to you today. Makes my heart hurt to read your words, but I know its the right thing to do. You have other children to protect. They deserve it, too.
Hang in there, find an Al-Anon meeting if you can. My home group is mostly parents of addicts...they really support each other.
I am sorry you are going through this...hoping for a little peace in your family now.
~T