Lose some belly fat in 3 weeks?

okay so, im going on vacation in 3 weeks down to where my family has our beach house and we are going to be going to the beach ALOT. I am wearing a bikini but i have stomach flab and i know i shouldnt focus on it but i try everything and its just so stubborn! i run 6 times a week (4-5 miles) and go to intense morning cardio cles and intense kickboxing in the evening and we do tons of different stuff and pushups and situps and it just doesnt work! i eat good because i lost 25 pounds this summer and would like to lose 20 more before september (going to be a senior in high school) what are the BEST flat stomach foods and what did you do to achieve a flat stomach? Did you follow a diet? have a workout schedule? i fluctuate between 149 and 152 and i want to be 132 by september i just need to get of this flab! and some side fat. help!!!!!