Glad your here. You really sound lost and confused, I am lost too. I have to wonder why at 17 years old you are into such hard core drugs. I think the meetings will be great for you, but I also think you need a therapist to find out what makes you do such hard stuff. Like what happened in your life at the time you starting using? I believe that when you find this out, you will have a better view on getting better. As for just doing it on weekends, we have all been there. Saying to ourselves, Oh I've been so good, what is one line anyways. Well we learn that 1 line leads to 2 then 3, etc...
You are young and strong (a strength you dont know you even have) start now and begin a life of happiness. Otherwise you will hit bottem. You think this is bottem. Just wait and see
I will pray for you
Debby