GMAT Math

Helllo Everyone! just yesterday I had my GMAT test. and you are now probably wondering: why is she wrinting here if she took the test yesterday? well folks, the thruth is that I failed miserably at everything I did in that test.
my goal (even if I have to admit, I have not put 100% of my efforts in the preparation. Silly, Silly me) is to take 650+, the higher the better, of course.
Yesterday, after 2 weeks of semi-intense preparation, I took 620, 54 percentile in math. Well, I surely was disappointed - I relied on divine intervention for all the exams I had previously taken, and it almost always worked.
ALMOST, because if failed (or, I failed) yesterday, and my biggest problem was surely the quantitative part. I currently am an university student, and I studied maths up until last year, but the more I studied for the GMAT, the more I realized what I knew was not enough - I need to know more tricks, ways of reasonings, and especially, I really need to focus on time - a snail would laugh at my face.
Yesterday I did not finish all the questions in the time allowed (only for the quant part).

To prepare for this first test I bought "Fundation of GMAT Math" well, that is one unneccessary book. I am sure it is great for someone who never had math in his entire life - it surely does focus on basics. but that is it, and I needed way more than that.

therefore, I would like to know which other books would be useful to buy in order to PUNCH that quantitative part on the face the next time I am taking the test - I am already scheduling an appointment.

- Have a good day ahead!