Need to lose 7 pounds by next saturday morning?

i understand the health risks, gaining it back, bad nutrition.. ect. I just want some tips, if i eat 200 calories a day and I drink 2 liters of water. can i exercise everyday and lose about a pound a day? and if i lose the 7 pounds will it be a great difference in appearance? i would do it in a healthy way but i dont have time. im 5'3 19 years old and a female at 136 pounds. it seems like my problem area is my stomach its kind of pot belly like and i have muscular thighs but i have a alot of fat in my inner thigh area.