Open Question: Somebody please, PLEASE help me?

I am a 14-year-old girl, had terrible acne on my back pain all! Yes, this is super serious. This is annoying, because I need what I buy T-shirt, to ensure that the acne does not appear careul. I have an upcoming dance performances and the former are exposed at the back. I need to get rid of all my acne fast. I live in ym Dada River's younger brother, so I can not let a doctor ebcause they do not understand women's issues do not take me to a dermatologist. In addition, they would not pay too much for any treatment. Someone give me an effective, inexpensive way to clean up my back quickly? Thanks!