Faithfully,
If the meeting did not help, find another one right away. You need support. Listen to the nurse, she knows more than your son. He is trying to CONTROL YOU and get his way. I also am a mother of an addict and know how hard this is for you. You have to take care of YOU,the stress can cause all kinds of damage to your system. It will make you sick and who will be there to take care of you? Not your son, he is only worried about him. Sorry if I sound harsh and uncaring, but it took me a long time to work on me. The stress caused me all kinds of problems, some of them I am still dealing with. If you have a hard time talking to your son, than don't . Talk to his doctor or nurses, and only speak to him when YOU want to. I know the feeling of missing your son, I miss mine everyday of my life, but know he is in good hands, his Higher Powers.
Take it one minute at a time, take deep breaths, and try to relax alittle. Easier said than done, I know. Turn this over to your Higher Power (HP) and ask him to guide you to do the right thing. Right now I think the right thing for you is to do nothing unless you hear from the doctor or nurse that your son is worse.
Hugs coming to you from another mom