You don't say how old you are but I'm going to guess less than or around 18
I sounds like a form of acne. I'm not positive about this tho. If you are given anitbiotic therapy, it is a long term thing. What I mean is, you would have to continually take it for it to have an effect. Even then it would not cure it or maybe not even stop it. It would just keep if from being so bad.
I would see a dermatoligist. He could accurately diagnose this. Sorry I couldn't be more help.