Daeva,
like it or not, it is an addiction. If you ask yourself if you could give up your SI forever and honestly can't say no, then it is an addiction.

When you cut yourself, your body releases endorphins that give you a type of high. You may not feel euphoric, but probably a sense of relief and reprieve of the feelings that made you injure yourself in the first place. It may not be a drug as you think of one, but rather it is a self made drug.

The other problem with SI is that it is a poor coping mechanism. When you don't feel good about something or are pissed off at yourself, you self injure. You need to find a healthy way of coping with your problems. The longer the SI continues, the harder it will be to stop.

Sam2