How to get rid of that last bit of flab on my stomach?

hello,im 14 and last year I was a lasy couch potato and fairly over weight. then I got serious with my body and starting taking drastic measures,swimming 6 hours a day,starvation diets,and lots and lots of abs,flexing them,crunching them and who knows what.my hard work has paid off,however im still not content with my figure i have the first two abs and i can see the outline of my bottom 4 clearly,I have a v shape bellow my last to. i recently got the iron gym and it works really im so impressed with how fast the results came,any ways when i sit down rolls of flab build up and the abs tend to disapear but when i stand up and extend my skin there clearly visible.my question is how do i achieve my six pack and shed that last bit of flab,what should i eat?if i had to describe my self im pretty slender but im kind of a skinnt fat.any help would be nice and preferably under a month because prom is coming;) many thanks to everyone.