Im not sure this is the right forum for your question, maybe someone knows something, but i will send a link i just looked up on self harm for you. Not sure it's helpful but worth a look. Please get some help for this, your so young and don't need to be hurting yourself like this, you are worth so much more:)
Cutting is self harm to be straight up. It's also a form of hurting oneself, so that you don't feel emotional pain, then you rely on it. You really need to see a psychiatrist, before you do anymore damage. I've seen folks who cut themselves so badly over the years, they can't enjoy life, they have scars everywhere.
You have to sit down with a professional and figure out what caused you to do the cutting in the first place, and then move from there. If you can't feel you can stop, I highly suggest you go to the hospital while you are still underage. If you feel you are doing more then cutting, and wishing to die, go to your ER immediately!
Like you I also suffer dibilitating depression and anxiety. Although I am not a "cutter." I can udersatnd why you do this. At my worst my head and brain would hurt so bad with depression and anxiety that I would slam it on my door HARD because the physical pain gave me another pain that distracted me from the hurt inside.
(not to mention that at my worst it feels like my brain is mush and pouring from my skull)
This cutting is not unusual for some depression sufferers because they use it as a form of relaese from the torment. Regardless, you know it is not healthy to do and you need serious treatment to help you get it under control.
I don't know what kind of treatment your getting for this problem now, but if it is minimal then you need to look for more intensive therapy and even meds to help control this compulsion.