Your body is still changing. When I was your age I weighed 127 (5'6") and that continued until I was 26ish. But, my whole distribution changed around; I had a large butt :-) and that got less and my waist got to 24 inch and all my sizes of clothes changed but my weight did not.

Work on thinking about something else to concentrate on for awhile; grades or friends or something? You know how to eat healthily so let yourself take care of that "unconsciously" and just eat as if it is a "chore" and concentrate on something else. My best friend at your age was a "jock" and she "made" me play hockey, etc. if I wanted to see her LOL. When I'd call her at home she was always in the shower (because she was always sweaty from playing some sport :-) I went to hockey camp in the summer (and I was a pretty crummy player and HATED running up and down fields) and had to buy full shinguards because she was so good I was getting bruised up. Figure out some other place to put your awareness!