How can i lose weight fast?!?

im 13, 5'3" im 124.5 pounds and i feel like i should die because im too fat. im really "thick" and i have a big belly and i usually like stiffen my stomach in school to make me look a little skinnier...i have really fat legs and my arms are like pretty much fine on the lower half but the top parts are really "flabby"...im going to darrien lake in 2 weeks and i want to be like 115 at least...what should i do and im really going to try to loose weight...i didn't actually "go through with it" whenever i try to do it. i can run long distances...but it doesn't seem like it helps at all...because i measured how much i weighed before i ran 3 miles without stopping and i got home and i checked how much i weighed and i was the same weight...so i don't think that works verrry well. please i want to lose 10 pounds in 2 weeks....i don't eat breakfast but i do eat school lunch usually at 10:30 (i have lunch in school then)...not the whole thing though just like the main thing not the vegetables or anything...i usually have a bag of chips at like 2:45 because thats when im waiting to get to track (i was in track but it ended yesterday) and i usually eat dinner until im full and can't eat anymore.....please i need help im not going out to buy and pills or weight loss things just home stuff...or if there is any diet or something that will help me eat less...? please 10 points to first person whos sounds the best! please please i need help!