What am i doing wrong?

I'm 13 years old i'm almost 230 LBS... uasually my day goes like this...I wake up I eat whole wheat crackers with milk or just bran cereal and i fast walk to school so once i get tired i keep on going once i get to school i just do my work like any regular student till gym im rlly fat so i try to drive in best as i can in basketball then in gym...Im one of the fastest swimmers in my cl but i wear a shirt so my cl mates wont say my are big like a womans then i keep going on my day till it's over then when i get home uasually i go out side and play basketball after i eat somethin healthy and on week ends uasually i just rest till monday mornin so what am i doing wrong? i dont eat much and i exercise alot..