Help severe depression?

I can't get off drugs because besides my mom they are all I have, Been addicted for more than a year to oc, ecstasy, and alcohol. I do other drugs occasionally. I've suffered from depression for years, been abused emotionally and physically, molested, dad killed himself, addicted to cutting, and can't afford counseling. Been to a childrens center for cutting twice last year. Only a few days tho. I can't get over my past. Being taken from my mom for years and seperated from everyone I loved to be abused. My friends are all drug addicts and my mom is depressed herself. I'm doomed cuz I can't do this alone but refuse to talk about it. Everyone is overwhelming me. I dropped out of school without my mom knowing even cuz I can't care! I just hurt and I have no clue how to get help..I'm sick of being sad and having my friends overwhelm me. None of them really care about me. Just everything is about drugs or gettin messed up? Or trying to get in my pants. My depression won't leave. I can't leave my mom tho cuz that is so selfish...How to get help?