Welcome to SR......I'm glad you found us although I'm sorry for the circumstances that bring you here.
My recovery began when my son went to rehab four years ago. No. I am not an alcoholic or drug addict........I am a co-dependent. I had no idea what the term "co-dependent" meant at that time. I wish I knew then what I have learned since that time and am still learning now.
My best suggestions are to read, learn, and explore yourself. And allow him the room and freedom to explore and examine himself.
It's such good news that he is in treatment.
gentle hugs