GMAT Strategy

hi guys,

well i have like half a dozen of frens juz done with their gmats n news is really bad......all of them scored like 650+ in gmat prep tests( both of them) n in reality they ended up with mere 500 odds......this has really scared me a lot.....
general preception quat is getting tuffer with verbal maintaining its level.....
pls can any1 tell me whr i can find more tuffer question for both verbal and quant.....
og is taken far too easy.....pls guide me i m kind of traumatized...
m done with og and review....pls some experienced person guide me what should be my line of action.....i hav gmat on 10 sep....n m kind of low in confidence...

thx in advance!!!