Open Question: I need ideas of what to do about my back pain?

Okay i jus turned 14 not long ago, I'm 5"1 and I weigh 105 and my back pain is really bad, my bra size is 34c, I'm suposed to be a 32d or something but the straps never fit so I wear 34c cause the straps and cups fit good but should I get a custum fitted bra to help my back pain or should I go to the doctor and see wat they can do? Like give me pain pills to help the pain., please help