weightloss plateua (help)

ambitionjr

okay at the beginning of march i started off at 174 . i started eating 1500 calories and exercising once a day (30 minutes exercise aerobics video) . during the summer i dropped by june i was 160 . i dropped down to 1300 then later 1100-1200 and ended up being 144 at the end of the summer . so the problem came when i went back to school ( 12th grade highschool student) . i only lost 1 pound since august 27 and i gained 2 back( i took a week off thinking that would get rid of the plateau) . the diffrence between summer and school year . is that i exercised more . i read somewhere that exercising more could prevent a plateua . but it didnt . i have a weight training class for 35 minutes and play fast pace basketball at school for 30 minutes and sometimes exercise when i get home . and i also exercise 7 days a week . so basically some things i have tried to get past the weightloss plateua are 1)take a week off 2)lower the amount of exercise 3)eat more:1500 calories:4)zig zag calories(900,1800,1000,1800,1000,1500,1000) . and none have worked for me . so i have two ideas 1) zig cag my calories again but a bigger diffrence ex: 2500 , 1000 , 2000 , 900 , 1500 , 500 , 1500 or lower my calories down to 900 and hope that i can lose the rest of the weight without plateauing http://www.myfitnesspal.com/food/diary/ambitionjr . btw i know my foods arent neccesasarily super duper clean but this what has worked for me in the past . you dont have to eat only veggies , chicken and beans to lose weight . thanks