If you have only limited time then you should give more priority to official gmat guides and gmat prep tests than any other prep material.
Try to identify your weakest area , spend more time on it rather than just attempting more tests just as I did during my first prep phase.
For example my weakest area is SC ( still my hit(right/wrong) ratio hovers around 70% unlike CR and RC where I can consistently hit above 90% ).
I used to read explanations from OG only for my wrong answers ,but you should read all the explanations even for the ones which you got it correct.Though I read about it many times in gmat club posts many times I decided to skipit to rush upon,but reading through the explanations of the correct answer choices will offer more than you actually think.
OG explains not only why the answer choices are wrong but also what should be added/removed to the wrong answer choices to make it correct.
prep source I prefer
Gmat official guides ( do all the problems until you got everything correct)
GMAT prep testsManhattan Gmat
cat tests ( you get in gmatprep as many number properties problems as you get in MGMAT tests)
Though I don't have expertise or score to backup whatever I wrote ,just my two cents
all the very best for your prep and exam