I need help losing weight and finding the motivation to lose weight?

So I am 14 years old, 5'6", and I weigh around 140. I always tell myself that I need to lose weight and the next morning I start of great but by the afternoon I;m munching on pita chips. I have no motivation. I've tried journals, weight watchers, nutra system, everything! Everyone says I look great but I when I look in the mirror all I see is fat and its effecting my summer. I dont swim with anyone. I dont go places. I need fun but my fatness is keeping me back. I'm actually musclely but I have fat over it. I just need some help finding motivation and a good plan.