At the moment, focusing on specifics is probably not the best route to success. You need to completely redesign your study plan. So before we even think about the details, let's look at the big picture.
The "on-off" strategy simply doesn't work. You need to fully commit yourself to achieve a good score. And two months of study is not enough time for most of us to prepare.
Any foundations book, while perhaps an okay start, is insufficient for anything beyond the 500-level. I also suspect that you lacked enough time to fully absorb the material from the two Manhattan guides mentioned. If that is the case, then you basically didn't incorporate any guidebooks. And the OG material wasn't even fully completed.
Based on this information, I suggest:
1. Guidebooks - Buy the Manhattan math series and the Powerscore CR Bible. Study the Manhattan SC guide.
2. Question Practice - Finish all of the problems in the OG Quant, OG Verbal, and OG12. Use them alongside the
Manhattan books. Complete the two GMATPrep tests.
3. Dedication - Study everyday for at least two to three months. Finish all of the books, and re-read some if necessary. Create an
error log and become an active member on GMATClub to improve and stay motivated.
For an
error log, you can find many different approaches on this website. But the
error log is just a means to an end and shouldn't be anything too fancy. Just mark down what type of question you answered incorrectly and the reason why your choice was wrong.