Is something wrong with me??

Rebecca • My nick name is Becky. I am 13 years old. I play soccer an take it very seriously. I`m known to be fun and funny. :P :)
Okay. So, I don't eat breakfast in the mornings, and so throughout the day my stomach hurts. Then, when it's time for lunch, I don't even get through half of my food before a pain hurts my stomach and I feel full, but I'm not. So I've been eating less and less everyday. And I'm loosing weight, it's kind of scary too. 
Opinions?