What helps get rid of acne?

I'm 17 and have never had any skin problems until 4 months ago ironically it coincided with a complete health diet no sugar no fat so that's ironic. I'm so upset because I've been so good and it's getting so bad. I need someone to tell me what to do to get rid of it. There are so many pimples!!!! Please help me. What gets rid of acne?