If you're referring to self-harm then it is important not to
stop cutting without having another coping method in place -
self-harm occurs when an individual lacks normal coping methods,
thus stopping leaves people unable to cope with negative emotions
and this can be harmful.
Often those who stop self-harm without another coping method in
place will eventually cut but do so far more severely than they
would normally, they may not be able to cope so may see worsening
mental health issues or even become suicidal, and some people may
engage in other self-destructive behaviour like drugs. If you want
to reduce cutting then try to avoid situations that make you want
to cut, also look at methods like drawing on yourself with a
ballpoint pen or flicking yourself with an elastic band.
It's best to talk to a professional to identify why you lack normal coping methods, find new coping methods, identify triggers, and resolve problems in your life.
If you are referring to slitting your wrists, I can give you an answer to that. In fact, I have personal experience with it. To start, surround yourself with people you love (i.e. your friends, boyfriend, etc.). Second, find out what is happening in your life that is causing your problem. If it is a family issue, try staying at a friends house for a night or taking some time away from home. If it is a relationship problem, try to forget about it by talking it out with a close friend or find someone new (or do what I did, take a break from relationships for a few weeks or months). Try not to get your parents involved because they may take it the wrong way. I almost went to a mental hospital, and I am sure you don't want that. If you do end up stopping, try donating to the To Write Love On Her Arms project. You can purchase their t-shirts at Hot Topic and their official website. It helps emotional and suicidal teens and it is a great organization. I understand what you are going through, and try your hardest to look to the future with hope for the best. If I can get through it, I am sure you can too. [:
If you need anymore help, email me at firstname.lastname@example.org
Hope this helped!