http://www.reddit.com/r/acne/comments/nrkg2/the_redditors_guide_to_acne_version_2/

Try Proactiv. It seriously works. The only caveat is you have to use it every day for it to work.

Other than that... Most acne is caused by stress and hormones. I'm gonna go out on a limb here and assume you're a highschooler. Unfortunately, highschool is very stressful, and there isn't much you can do about that. Try and remove some of the stress from your life. I know after I graduated from highschool my acne all but disappeared.