AMD793,
It feels that you have problems in timing. Read
this MGMAT post. Specially work on the 1-min sense. Let go of a difficult quant problem if you are spending more than the allowed time.
Focus on OG. OG is the best material to study from. I did the same mistake of saving it for the last. Anyway, focus on it now. Don't just solve, read the explanation and really learn the content so that if the similar problem appears in the test you can answer it.
You still did not reduce your load. Rather pumping up to do even more study. The link I provided is a scientific research, not just some online junk found on the net.

It came from a book called periodization.
So practice on your weak areas, focus on the official material and review the answers and take planned rest (maybe not exactly like the way mentioned in the post, but at least a reasonable amount of rest). Most importantly, do NOT overdo and do NOT panic. It's just a test!
(BTW, please take my advice with a grain of salt. My last GMAT was a disaster. I learnt from that lesson but did not prove myself yet.)