Hi sidsrinadhuni,
From everything that you describe, there are a number of different issues with your studies and timeline:
1) With your current Test Date, you only have about 1.5 months of study time remaining, but you will likely need far more time than that to hit your Score Goal. While you don't have to change your Official Test Date just yet - and there's no harm in taking the GMAT as scheduled - you will almost certainly need far more time than you've allotted to hit 680+.
2) The Verbal Study Plan that you're currently following doesn't appear to be leading to improvement. Maybe that plan is fine and you're not properly following it... but maybe it's not a good plan at all.
3) You don't have a Plan for approach the Quant section - and with the exception of 'Inequalities', most of the subjects that you listed are relatively rare (meaning that you'll likely see each just once on Test Day. By extension, there are almost certainly other areas in the Quant section that you should be working before you put too much energy into any of those listed areas.
This is all meant to say that you would likely it beneficial to invest in a GMAT Course of some type (either Guided Self-Study or instructor-led). Most GMAT Companies offer some type of free materials (practice problems, Trial Accounts, videos, etc.) that you can use to 'test out' a product before you buy it. We have a variety of those resources at out site (
www.empowergmat.com). I suggest that you take advantage of all of them then choose the one that best matches your personality, timeline and budget.
If you have any additional questions, then just let me know (and you can feel free to contact me directly at any time).
GMAT assassins aren't born, they're made,
Rich