First, it's better not to set up a do-or-die situation. And this is especially true at the 750 level. To be sure, we encourage you to aim for the highest score possible, but please don't create a situation that creates undue stress. This only invites panic, and at that point you're no longer in control. Please don't give in to that temptation. Remain calm and stay in control.
But now to address your post. Yes, I think that the Manhattan SC guidebook, the Powerscore CR Bible, and the corresponding
OG material form the ideal preparation for the verbal section. Make sure to fully read every single
OG explanation. Every single one! And take an active role in the verbal forums; answer questions, defend your choices, and debate with others. These activities help quite a bit.
Also, look into some
GMAT Fiction for a productive way of taking a break from your GMAT studies. Yet another option concerns the RC questions. Practice with some LSAT passages for an extra boost. And if you're particularly weak in RC, consider an RC guide. The Powerscore RC Bible, while excessive in most cases, might help.
Perhaps one the most helpful comments that I can offer is this:
re-read the books! Re-reading the verbal guides is, in my opinion, necessary. Keep doing this until the concepts become second nature to you.