GMAT Strategy

Hi,
I don't know if some one can advise me on how to get a grasp on whats going on with my scoring . Ok let me give some background i have been prepping for 6 weeks now and have used Princeton, Barrons, Kaplan Uk edt.
I recently got OG 11 like 2 days ago and have just started working the problems.It seems like a lot of Q 's ANY RECOMMENDATIONS ON WHERE To focus my time in this book. Diagnostic test results at above average in all sections.

i find the Kaplan most challenging as far as both Match and Verbal.
Initially DS was a total mystery to me and i was spending way more time than 3-4 minutes. I have got better now but some types of Questions i just pass on because i believe its going to take too long to solve.

My verbal is pretty strong and when it come to practice problems and i am getting above 80% on all three sections when it is untimed practice.
But as soon as i move to a Timed environment IE: CAT Tests my scores drop like fast, and it is primarily in Kaplan/ Barrons. The same can be said for Quant and DS questions in the math section.

I just feel so panicked and keep watching the clock and end up rushing through the test after the initial first 10 Questions and end up guessing rather than solving the problems after that. Even after doing that i am still short of time by like 5-6 Questions in Math.

Verbal seems to be vice versa where i seemed to have 2-3 minutes left but end up to find my SC Result pathetic on the 2 CAT'S taken to date.
(Kaplan 1 and 2).

What do i do? How to improve my test taking timing on both sections?
Especially quant i am worried!!!

Help I have 3 weeks left and dont have more than 2 hrs a day to spare how to use my time most wisely?