The good news is, math is easier to improve than verbal. 39 verbal is quite good, but 33 math can be improved significantly.
See if you can identify which concepts in math are the trickiest for you, and then get a basic high school math textbook and refresh yourself on those concepts.
There's a limit to the math concepts you'll see on GMAT. Geometry, number propreties, algebra, laws of exponents, rationals and fractions, rate and work problems, some probability and combinations, the occasional cartesian coordinate system problem, and word problems. I think that covers most of them.
So just make a schedule of the areas you need to review, and spend a week or so on each, practicing problems and also studying the theory. You should see a large improvement within a month.