Hi Baracuda,
Good job on your prep so far. It can be concerning to encounter tough questions near the end of you preparation. The questions on this forum tend to be the toughest of the tough so don't worry about getting them wrong. Use them as learning tools to fill in those last few content gaps. That said in these last ten days I would focus mostly on Official GMAT Questions: Take your last GMATprep CATs, GMAT Focus (1-3), work through all of the hard questions from Question Pack 1, work through your
error log, and revisit tough questions from the Official Guide. Use this time to consolidate the knowledge that you have rather than adding new knowledge. One thing that my students have found helpful is to make a formula/strategy sheet. Basically writing down everything that you are trying to remember.
Considering where you are already scoring you know enough GMAT Quant to get your score. You just need to apply what you know. It's also important to have your timing down. Here is an article on
strategies for the GMAT CAT. Maybe it helps. Let me know if you have any questions!
Happy Studies,
A.