Good diet for me?!?! Cant lose the weight that I regained..?

I am 5'4'' and 17 years old. Two years ago I was about 150 lbs but then I lost 35 lbs so I was about 115. Over this last winter I gained about 10 pounds and I've been trying to lose atleast that weight if not more. Ive stayed the same weight for the last three months but cant seem to lose it again. Ive tried everything- dieting and working out. I try to limit my calorie intake to under 1200 calories a day and I eat super healthy like rice, oatmeal, salads, veggy burgers, and fruit smoothies etc. I also run between 2 and 8 miles every day depending on how I feel that day and I go on a bike trip atleast twice a week. All my friends seem to do nothing and eat tons and somehow manage to stay super skinny. I know I am not technically overweight but I don't feel as thin and in shape as I would like to and I would ideally like to be about 105 lbs. HELP! What do I do?? miracle diet anyone?