Medical bills

Hello, my name is Sabrina, I'm 19. About 6 months ago I was in and out of the hospital a few times for kidney stones, kidney infection, and ovarian cysts. I'm fine now, but when I saw the medical bill I almost had a heart attack. I tried my best to pay what I could but I am only making so much money between paying bills and wanting to go back to school. The hospital actually sent it to collections because I didn't pay $200 a month, I paid $60. atleast I was paying it, right? I seriously don't want this affecting my credit score, or affecting any thing else.  Will you please help me?  Thank you.