Diet and Natural Weightloss

Hey guys, I’m 12 years old, 5′2, and weigh a wopping 190 lbs. I am trying to lose weight, but I feel like I may be eating too much, not exercising enough ect… Anywho, doing this, how much weight do you expect me to lose a week?

B: 1/2 cup Kashi Go-Lean crunch, 1/8 cup Blueberries, 1/2 cup Lowfat milk.
S: Small yogurt, 1 tbsp all natural pb.
L: 3/4 cup lowfat cottage cheese, 1/2 chopped apple, small handfull halved grapes. 1/4 cup chopped walnuts. 1 wasa hearty wafer.
S: Florida naval orange, 1 tbsp all natural pb.
D: 1 grilled chickin breast, boneless, skinless. Broiled broccoli [sometimes asparagus]

And I drink as much water as I can but feel sick so only about 34 Ounces a day.

Exercise:
Walking 45 Mins.

Is this enough to acheave a 70-80 Pound weightloss?
I get really hungry though. I go to school and have to eat at these times…

6:00 am
10:30 am
12:45 pm
3:00 pm
6:00 Pm
Lol I Forgot To Mention I Am A Girl!!

HAHAHAHAH! Lol, No Offense Taken teehee