If you weren't retaking the test so soon, I would be able to give you better advice. I got 96th percentile for verbal and only studied for a month. The key is to study A LOT of vocabulary. I made roughly 3000 flashcards. Quizlet has a lot of sets you can get, but I recommend Barron's. You also have to practice reading complex material, which will help you with your vocab and also help with the reading comprehension portions. I recommend NY Times, the New Yorker, TIME magazine, Newsweek, scientific articles, anything else you can get your hands on. Whenever you find a word you don't know, look it up. You should also be taking practice tests. I did one everyday for 2 weeks before my test. Good luck. Try to stay calm during the test, and don't get hung up on questions you don't know. Be sure to guess since you do not get points off for incorrect answers
As far as scoring lower on math, just do a lot of math practice tests. Review any relevant formulas before the test, and you should do fine.