Arthritis pains; back pains?

I'm 13, and my mom noticed swelling in a few bones in my back. Before i thought it was arthritis, I was thinking of consulting a doctor. We don't have enough income to go, though. But the pain in my back is excruciating, enough to drop me to my knees and scream. I'm staying away from taking too much of an over-dose of aspirin, which makes me sick and wears off fast. It hurts as soon as I wake up, and gets worse by the hour. I really don't know what to do to make the pain go away, pain-relievers that I've tried don't work; Aspirin, Tylonol, & Benadryl. Is ther anything stronger that I could take with my age? Or should I go to a doctor? Advice?