I can’t loose it

I’m 15. I’ve always been a big girl but it never really bothered me till now I work out for 4 hours everyday ( swim team) and I don’t eat like ever, I’m 5,8 and for some reason I’m 250

Why??? I’ve been trying so hard I don’t get it.

( and if you dont know swimming is like track burns more calories than you eat in a day).