Bladder hurts!? don't know why?

I woke up this morning and had a BAD ache in my bladder. It hurt so much to each just walk. I didnt feel like i had to pee but i did anyway. It didn't help. My whole crotch area (sorry if thats tmi) hurt just to walk and i felt sore down there. i;m only 13, ive not had sex. help please!?