Diet and Exercisse?

[hakukid13]

I'm almost 15 yet I'm 200lbs; even though I'm about 6 ft. My parents keep saying I'm just big boned but I really want to lose weight.

Everyday I go 15 minutes 3mph and 5 minutes 6mph on the treadmill going at a 1.5 slope, I pull back on my bow (47lbs of weight) about 50 times, I go 10 minutes on stationary bicycle which ends in 1 2/3 miles when I'm done, and I go on the stair stepper 100 steps. I might do 20 minutes on Expert DDR though for a workout sometimes.

____
Since I'm on Spring Break I don't go to gym at school, but I have HOPE and Individual Duel Sports which I walk for 20 minutes in both classes and do whatever they have us scheduled.
____
I eat wheaties ( for fiber) in the morning before school, a Dr. Pepper and granola bar at lunch, and a normal dinner (depends) at night then the rest is probably just 3-4 glasses of water.

What can I change into something else which would make my exercise and diet even better? I lost 2lbs so far because I started Saturday.
Also, I want to get around 180-170lbs by the time summer is over in August so about 4-6 months.