Hi Videep, I can totally understand ur position. I had same experience last year. ended up 550 though in mocks I was getting easily 600-680;
Now to answer ur question, since u are determined to write exam so soon, Solve
only official questions;
https://gmatclub.com/forum/search.php?view=search_tagsTopicwise (ex. CR, weaken, sub-600,
official guide(and gmatprep quesions)) ; I think next 2 weeks should be invested
focusing on your weak-area and using official questions (to tune your ear/mind to be acquainted with language and complexity level); First make sure u are able to get all 500/600 level question "Correct" before attempting 700; As this is the same way, gmac algorithm works;
Also U can easily improve ur Quant score;
As u diagnosed about practice stamina,
solve 31/36 quesions in one Go; in a day u can give atleast 2 timed-stamina practice;
Do assess yourself well and
ACCEPT all the shortcomings then plan(realistically or according to ur personality) to improve;
Also just think about all the possibilities(regarding score) beforehand, to tackle the anxiety;It is difficult to improve score (by 200 points)in very short time , but it is easily possible to get better score .