How to maintain my appetite as well as cravings?

Okay well I'm not over weight but I feel very fat for my age and i feel as if all my friends are skinnier then me :\ I know I know, everyone has body image issues but I don't think people know just how down on myself I can get. I go to the gym almost every day or at least second day, and I try my hardest to eat healthy foods. I never skip meals, I always have breakfast then recess then lunch then a snack after school and then dinner. Lately its been really really hot though and I've noticed I've been extra hungry, especially for sugary and fatty foods. When I eat like that I can't enjoy it any more and I get really upset. I didn't have a great diet as a kid and I think its effecting my teenage years, even though I eat quite healthy now. ANYWAYS my question is, is there anything that I can do to help satisfy my sugar cravings? Foods that are filling and good for summer. THANKYOU :)