High Volatility in GMAT prep Scores (GMAT prep test-free and paid)

I have the Mongoosh Subscription and have been using the account for GMAT prep for the past few months. I have practiced and revised consistently using the mongoosh account. In the last mock test I took on mongoosh the verbal score was V35.
Then I took the first two GMAT prep tests;-
Test 1: 670, V33
Test 2:- 700, V35
After the second test I felt confident that I was close to my target score of 700-710. Infact, I was trying to push for a verbal score of V36-V38.
I just wanted to make sure of my performance from more tests, so I purchased GMAT prep Pack 1 and 2.
To my surprise, my scores in verbal in these 4 tests have been very poor.
Pack 1, Test 1: V25
Pack 1,Test 2: V31
Pack 2, Test 1:- V26
Pack 2, Test 2: V8
I feel completely lost after taking the last 4 tests.

I have a few questions for official GMAT prep practice tests:-
1. Why is there so much of deviation between my score in mogoosh,Official GMAT prep (software) test 1,2 and the score in official tests of gmat prep in pack 1 and 2?
2. Has there been a change in computation of the percentile score by GMAC in the recent past?
3. Now the test allows us to choose the order in which we want to take test- quant, verbal, IR. Does the selection of order affect our score.
4. Could you analyse the above issue and tell me a possible strategy to address the issue. I have planned to take the GMAT on 10 september,2017 so I have another 15 days to address the issue.
A few more observations made while test taking:-
1. The no. of questions I could attempt properly was 32 no.s (got V25, V23, V31) , the rest I had to quickly tick and complete the test. In GMAT prep test 1 and 2, I attempted 34 questions properly and still got a V35.
2. I tried to change the order in which I was took the tests- From Verbal, quant, IR to IR,Quant, Verbal but found no significant change of score in Pack 1 of the paid GMAT prep tests.
3. My expected score in mongoosh subscription in V40!! After solving all the verbal questions but the score in all the GMAT prep tests are discouraging.
4. I do feel a bit of panic during the test specially in answering CR and RC under time limits. I have very good accuracy in CR and RC, but in the GMAT prep tests, my performance is very volatile.


PLEASE HELP. I WISH TO QUICKLY COURSE CORRECT AND GET TO A SCORE OF V35-36 by SEPTEMBER 10. I have achieved the score in 2 tests. So I feel I can do better.
My strategy is to reach Q49 or 50,V35 to reach 700. So i need a few days to prepare quants. But unless i can be sure of my verbal scores, I am unable to move over to quants. I understand that a small increase in verbal score can make a big change in the overall score.