I'm 33 years old and I used to cut throughout high school, college and even into my mid twenties. I don't know what changed, but seeking help and finding a support system(perhaps here) could help you. Sometimes I still get the urge to hurt myself, I tried getting "professional" help and they were on their own planet, not realizing that every person is different and needs a different approach in treatment. I know how difficult it is to deal with parents or friends who just don't understand. I kept getting the "WHY? WHY? WHY?" question...
The important thing now is to get the help you need. You realize it's a problem and that's always key.... Don't let it turn into something worse like suicide or something that seems less, like becoming an alcoholic but it is just as bad... I'm still working on getting my life together and I've found something that works for *me*. I may be married and have kids, but it's hard to get rid of the cutting mentality because it's how I handled stress throughout high school. But the sooner you can learn how to deal with stress in non harmful ways, the sooner you can get on track.
Also, now that I am an adult, I'm really embarrassed by the some of the scars I have left on my body that will never go away. It's a reminder of the pain I went through, but it's also a sign of my weakness of letting other people get to me, who in the end, disappeared out of my life and never really mattered. I really believe we are all strong and confident in our own settings. For me, I threw myself into studying and learning everything I can about well, everything. Find a distraction for yourself. You don't have to make yourself stand out because of the negativity that surrounds you. It's hard to do, but I made it through and I believe that you can too. Start with the ice cube, or a tray of ice cubes....you'll get there....I'll try to be here for you if you need it...