Hello Rosita and welcome to SR. You will find many many resources here to assist you in learning more about addiction. Most of the Momma's here also post in the Friends and Family of Substance abusers so you will also get responses there. My son is 27 and has been struggling with addiction for 7 years. All I can share is that no matter what you want to do or not do, unless your son wants to stop, everything will be pointless. I have swooped in so MANY times to try and SAVE my son, all to no avail when he decides to use again. I detached and started to give him the space to do what he wanted to do. He has been homeless and out of contact 3 times in the last 7 years. It aches when they go "dark", but you are absolutely correct in that he knows that his using is hurting you and he doesn't want to answer to that. My recommendation is to read and share here. Many of us have been exactly where you are now. Also, if you are comfortable, look for Alanon meetings where you will be able to get face to face support. I will send a prayer for your peace and acceptance that you did not Cause it, You cannot cure it and you cannot control it.
That is a very powerful concept that get a hold of to help you with your feelings of guilt or sorrow.
Hugs from one Mom to another.
TT