How to cure Chest Acne and Back acne?

I'm 15 years old and female. I'm pretty sure it is in my genetics. My face is perfectly clear, maybe one or two unnoticeable blemishes. But my chest, is like red and has blemishes that covers less than a quarter around the chest. The blemishes are red, not my actual chest. I have had back acne since i was little i didn't care much about it until i was in grade 8 and got the chest acne. I asked my doctor for some stuff even took pills they have worked but kind of dried out my skin which i didn't like. I have gone on Internet an searched skin types, what i have learned is that i have a normal skin (my skin has no visible pores, not very oily, firm, comfortable when i wash, i have taken several tests to make sure). So how i get rid of this? i cant take it anymore, i feel like crying. yes yes i know at least i don't have it on my face. but my favorite types of shirts our vnecks and i cant wear them bcuz of it. im so insecure about it. PLEASE! help me. thanks you so much i greatly aappreciate your help:)