Help Needed: How to improve from 680 to 750+ in a month

Hello gmat experts,

I took my gmat in Nov 2014 after studying for ~4-5 months and scored 680 (awa-6 and IR-6).
Material used:
- MGMAT all cats and SC,CR books (I am thankful to gmatclub posts that recommended mgmat. It is truly "the gmat bible" for me)
- Kaplan tests and books (I found the books to be pretty useless although tests are OK. Still it's scoring is off I feel.)
- OG 13, verbal review and quant review for extra practice.
- Some difficult questions from gmat club posts (but not all) since OAs aren't always available for every question.
- Veritas free question set.(found it quite difficult and of good quality)

Overall I had solved OG and verb+quant review 3-4 times easily and had done good amount of practice before the actual exam. Still, I believe due to pressure, I literally flunked my verbal with the score of just 35(I did not take 8 min break-BLUNDER!!). My quant was 49 because of which I think I reached 680. I was totally heartbroken because I always believed that my first attempt was the last attempt and wanted to give my 100% in it. After looking at this score I was saddened and didn't look at the study material for 2 months. Now I am back to gain back the lost ground and conquer my fear of failure.

Overall scores before the first attempt -
My aim was always 720+ but I couldn't reach that mark in MGMAT cats. I was always hovering around 690. In 2 kaplan tests and Veritas free test I scored around 710 and in gmat prep I scored 720. That is why I thought maybe I can reach 720 on the actual gmat. After some introspection I have realized that my strong points - SC and 600-700 difficulty CR - turned out to be my weak points on the actual test.

What I am planning to do now is to get SCs absolutely correct within 45-60 sec. and find out some strategy to destroy 800 difficulty CRs. Because in difficult CRs, especially after completing about 30 problems in cats, the already difficult wording seems even more difficult to understand and break down in 90sec. I really want to concentrate on this and raise the bar for CR.

I understand that SC and CRs are the relatively easier areas to improve than is RC. That is why I wanna make sure that I literally destroy every question of these types that comes in my way before my D-Day. I admit that I wasn't completely confident on my first D-Day, because I was under a LOT of pressure. I am going to work on this to make sure that I am calm and confident from now on. Now my target is 750+ because I do not want to leave any margin of error.

I would really appreciate if you could suggest me some innovative ways of achieving this goal and extra study material because solving the same problems again is not giving me a clear idea about my improvement.
Plan of record:
- Already solved OG and verb+quant review again.
- Solved a few veritas problems again.
To be done:
- Solve 1000 sets from gmat club.
- Solve all the 700-800 problems.
- Maintain error logs and track my progress
- Take each gmat prep test twice (Previously I gave each test only once)
-Take all mgmat cats, kaplan cats again and solve mgmat club cat. (Any more suggestions?)

Please suggest me new material that I can use and ways to tackle the highest difficulty CR problems. Also would like to know reviews about knewton practice problems and cats.

Thanks a ton!