Hang in there Corse!
I remember what it was like to be 18. I wasn't using anything at the time. It is a tough time. I remember being angry all the time.
My daughter is 18 and my son is 17. They both have a lot of angst. My son has been very vocal that the source of all his problems is because I am a junkie. I have tried to reason with him that I only used heroin for the past 18 months but he has been angry for the past 6 years.
It is great that you have family that you can reach out to. Try to do that as much as you can. I remember the first few weeks when I got out of the hospital. I didn't want to see anyone. But when I finally started to stop feeling so sorry for myself and realized that I was more angry at myself than anyone else, I really enjoyed seeing family.
I really think you should look into NA meetings. I have only been going to them a couple weeks now myself. I still haven't had the courage to actually speak up in the meetings yet, but just being there and hearing what everyone else has to say. It has helped me tremendously. I think it will also help you find some new friends that are going through what you are, but that are also trying their best to stay clean.
Everyone makes mistakes. Don't be to hard on yourself. I didn't start really making serious mistakes until I was in my early 20s. Keep coming back here. Please try and get to an NA meeting and give it a chance. My first meeting I realized that the guy on my left and the girl on my right could not have been older than my son. You are not alone.
I will keep you in my prayers. Please let us know how you are doing.