I have my GMAT scheduled for 21st September and have taken the next two weeks off to concentrate on the exam (Unfortunately, a lot is riding on me getting a good score

). Though I am usually very much in control of things, this exam is now starting to make me panic. Could someone please help me out with any advise/strategy to get me a 720+ score? Background - Indian IT Engineer (so non-native speaker with slight advantage on quant) with > 5 years of work exp.
My mock test scores (taken 2 days apart in the last week) are given below -
GMAT Prep 1 - 680 (Q48, V35, IR 4)
MGMAT 1 - 650 (Q45, V34)
MGMAT 2 - 610 (Q44, V31, IR 5)
GMAT Paper Test - 740 (Q49,V44) - I don't think this test really matters, I solved 75% quant without using a notepad
Potential positives - 1. At around 10-12 hours a day, I still have some time left before I take my exam.
2. In timed - practice problems (OG and
MGMAT), I am able to get > 80% accuracy in PS, CR and RC sections.
3. Haven't started the last 30-35% questions of each section in OG13. I was planning to study iteratively and though I should reserve tougher questions for the last week when I have all the basics ironed out. Hopefully this would increase my scoring.
Definite negatives - 1. Haven't been able to finish even a single section on any of my exams on time (worst case had me guessing upto 8-10 questions in the end).
2. Though, my SC accuracy is getting better, I am still lurking around 60% (way below what I want).
I am currently reading through the entire
MGMAT SC book and working on related questions.