Get a teacher!! Oops...sorry, wrong thread.
If it IS a hairline fracture, you need to set it and immobilize it right away to prevent complications down the road. My advice to you (and I am NOT a doctor.......although I play one on TV

) is to get thee to a doctor ASAP to find out what this is. I know you're in Mexico, but you're talking about a problem that may affect you the rest of your life. Good luck!