sorry to hear bout that, but congrats on your great quant score
this usually happens when u dont practice sitting for long hours,in front of computer screen,u must practice full length tests at least twice a week.Try petersons guide with Cd .
pls remember with more practice ur not far away from 700,
try princeton review
2005 with CD ,it has good tips on how to move thru the verbal with less effort.
relax and stretch during your 5 min break, go to restroom and have some tetrapacked juice or sugary drink for some energy 2 attack verbal section.
u can do all the above in 5mins break if u r prepared
remember to breathe throughout the test ,many people start holding their breath when the tension rises up