Unable to break the 700+ barrier - Need Help

GMAT Experts ,

I plan to appear for GMAT exam by August end. I started GMAT preparation few months back but geared up from couple of months back. I completed OG 13, and GMATPrep tests. However, my score remains same in both. 680 with Q50 and V32. In both the cases, I failed to sustain the momentum in verbal section after I crossed first 9 or 10 questions. In both the cases, only one question was incorrect within the first 10, but got around sequential 5-7 questions wrong, and then scattered wrongs.

After each test, when I analysed the questions, I tried to re-attempt those without time limit. And that's the way I practice. Surprisingly, I got most of them correct.

Hence, I am unable to figure out whether the strategy / time pressure / anxiety of verbal throws me out within that 10 to 30 questions slot. I tried to practice with bunch of questions - for example - 15-20 questions , even then I get 80% accuracy with no time crunch.

Surprisingly, in the last GMATPrep , I got 3 RC questions wrong out of total 12 RC questions , and RC ability in GMATPrep comes out to be 29%. So, going by the stats , I am getting more and more confused.

Any help from your side , and any guidance to shoot up the verbal score would be great.