Hi JPn and welcome. My son is also a heroin addict. Iwas also scared, confused, angry and hurting terribly and came here frantically looking for help and got it. There is a great bunch of loving, caring people on NarAnon who have been there and are willing to help anyway they can.
I don't know what's been suggested to you but what is very helpful is going to(face to face) Anon meetings
, there are also scheduled meetings right here on this site.
The book "Codependant No More" by Melodie Beattie(all books by her)is HIGHLY recommended
Reading the stickys on top of the Naranon boards
Coming back here and reading and posting
The 12 steps
I hope you Keep coming back and let us know how you are doing. You are not Alone. I wish you and your son the best. Hugs, Iamunique