Once you started to cut yourself you are past the point of self-help. It is time to talk to a counselor. If you go to high school, your high school most likely has a counselor that you can talk to, if you go to college, they have some counselors to talk to as well. (these counselors are in their path to becoming psychiatrist, but they are very knowledgeable). If you are working, then you should have a number you can call to talk to a counselor. I am not sure how confidential the work line is, and I know that they have to report anonymously that an employee is using their services to the company that you work for. If you can afford it, go to a private counselor. However the way, get help immediately. Cutting yourself can lead to other things that you might just be in time to avoid.
Get you help now! Wanting to cut yourself is a symptom of very serious mental problems, none of which should be messed with. It's nothing to be ashamed of; it's an illness, not a weakness or a moral issue. Talk to your parents, teachers, ministers, relatives, anyone who can get you medical and talk therapy for your problems. My son and I have done this and we're leading good lives. You can, too. Good luck!