GMAT Strategy

I've been shaking with the math section. There have been times when I've gotten 49 and other times when i get 38's. It's really frustrating. i took the GMAT and got a low quant score, 55th percentile. I know I can do well in verbal (high 80%) but quant im uncertain about.

I will be taking the test in a month and again in March. That gives me two months to improve my score from a low-mid 600s to a high 6-700.

Pls recommend what books to study from. I've done the majority of the questions in the Quant and 11th edition. any other good study guides?

Also, what should my study plan be? Should i study both verbal and math intensively or focus my efforts on just my weakness?

Thanks all