First, you're talking about jumping from 79th to 96th percentile in 2 weeks. Very few people could make that kind of leap in that kind of timeframe. What's more important - the score or the test date? You may have to choose: a lower score by that date or the chance for a higher score at a later date. Think about this now so that you can make a good decision about whether to postpone if it comes down to that.
Okay, so some stamina issues, definitely. Were you taking those practice tests under 100% official conditions - essay, IR? Did you start doing those sections only on later tests? That might be the source of the mental fatigue during verbal (and dropped verbal scores).
How much have you prepped for essay and IR? I know you don't care about the scores in those sections (much), but it's still important to do *enough* prep that you can get "good enough" scores in those sections without wasting too much brain energy.
Essay:
http://www.manhattangmat.com/blog/index ... no-thanks/IR: more complicated. When are you planning to apply? (The strategy I give you will depend a bit on this.)
Also, just a note: if part of the mental stamina issue is that you just didn't really learn essay and IR well enough... then that's another reason you're likely going to need a bit more time.
I don't know how, when and how many problems I can skip, since I am scared of skipping an easy problem.
Don't think about how the test rates the problem - you can't possibly know that anyway. Instead, base your decision on how hard the problem is for you right now. Try it. If it's driving you crazy, figure out how to make a guess and move on. DO NOT spend
extra time on something that is driving you crazy.
Timing:
read these two first (quick reads):
http://www.manhattangmat.com/blog/index ... to-win-it/http://www.manhattangmat.com/blog/index ... -to-do-it/Then start working on this (will take longer to read, but important!):
http://www.manhattangmat.com/blog/index ... nt-part-1/Note: timing is often a 4-6 week fix -yet another reason you may need some additional time. You can still make some progress in 2 weeks, but you won't completely fix the timing.
Finally, did you take our course? If so and if you haven't done your Post-Course Assessment yet, sign up for it now (in the Office Hours section of our student center). If you did a Guided Self-Study program and you haven't yet used your 2 phone sessions that come with the program, again, go sign up now and talk about building a plan with an instructor!
Finally #2: I thought of something else. Because mental fatigue has been an issue, it's CRUCIAL for you to make sure that you mostly rest in the final 2 days before you take the real test. (Everyone should do this.) No more than 2 hours MAX of review the day before and no more than 4 hours the day before that. Otherwise, spend your time doing things that are as non-mentally-draining as possible. Go see / rent that movie that you've been wanting to see for a while. Have dinner with friends. Etc.