Unfortunately cold turkey doesn't work. This isn't something you say you are done with and sit on the couch all day, you'll probably throw yourself in that position again and again until finally kills you.
You have already taken the first step and realized you have a problem, an addiction. You should take the next step and talk to someone, preferably a close friend, family member or someone with experience. Perhaps your parents, school councilor, teacher, friend, maybe a sponsor like Camel said. Look into and see what your resources are to help you.
Remember this though: if you want to change yourself for the better, you are going to need to going to commit and actually work toward it.
