Its this normal , or not ?

i am a very picky eater , idont like any meats , seafood , and i cant eat candy . the only thing idrink is water . and i exersize 12 - 14 hours a day . but everytime i wanna eat , i take like two or three bites and im completley full , and cant eat anymore . also i always count all my calories and what i eat , and i refuse to eat anything fattening ( chips , soda , candy . . etc ) my mom sais i always look tired too , and im almost never hungry . also i leave alotta food behind . i only eat about 900 calories a day . and when i eat something unhealthy ifeel guilty and work it off . also after coming home from my workouts i still workout some more . is this a problem ? BTW im 13 and an Elite Gymnast .