Body acne

So i’ve struggled with acne on my back and mostly my arms for quite some time now. I have a bunch of scars on my arms and it continues to break out with acne and i’ve tried many treatments but nothing seems to really help. My back has cleared but i’m embarrassed to go out in a tank top because people will see my arms and how they’re covered in pimples. I’m so insecure about it and i’m only 18 pls help lol