"I caved. I told him I don't support his choice and would not help him research detox remedies, but I agreed to control and hand out the pills during the wean-down process according to the schedule he proposed."
Has he started begging or demanding the pills yet...cause they are his? Will happen, mark my words, been there, attempted to do that. trying to control another is not the answer, cannot be done.
If you want to get healthy stop focusing on him, go to meetings and start focusing on you.
Step one is to open up a new account in your name only and don't give him your ATM card or pin #.
You have a child, he/she should be your priority...not him. He is an adult, he is responsible for his choices, good or bad. Your child will carry his/her childhood into adulthood, why not set a good example for him/her? Don't attempt to fool yourself, he/she sees and hears everything.