Hey, I'm sorry you feel isolated and depressed, however, I'm not sorry you got caught. Your parents do have the right to punish you, though I disagree with their methods. They should be talking to you and getting you help. They may just be shocked about their "little girl" getting into such bad stuff and not want to face you knowing the truth. You may feel like smoking relieves your depression, and it does, for only a little bit. But from what I can tell, you're already addicted which is what's making your depression worse. Cutting is the same way. There are too many health risks to list when it comes to smoking and doing drugs, so on to what you should do.
Do they come by your room or are there opportunities to talk to them? If so, please tell your parents that you're sorry and you know what you did was wrong and that you want to change. Then explain to them that the only way that can happen is if you're allowed to talk at least to them and a therapist or counselor. If you want them to trust you again, then you have to act maturely and not gripe or moan if they still won't let you see your friends. That's another thing. If these friends are smokers and drug-users as well, cut off your friendship with them. They'll only drag you down if you really want to change. Be honest with any couselors you decide to talk to and really do try to rid yourself of these addictions. Depression's a b**** and life can be too, but along with that bad stuff, life can be so good, especially without cutting, smoking and marijuana. Strive to live it to it's fullest, sober and without all those health problems that come from addictions. I'll be praying for you!
Just because everything's changing
Doesn't mean it's never been this way before
All you can do is try to know who your friends are...