GMAT Strategy

Hello,
After juggling with the princeton review/og-10(verbal part) for a month, I pulled up my socks and got the OG-12 on the 5th of DEC.
Further I got the mgmat guides(5 maths nd SC) nd d powescore CR on the 13th Dec.

Since then I've licked all the books including the OG 12(almost twice) as my quant was weak. M investing over 6 hrs a day in studies for the past 3 weeks.


I seem to do well in verbal in general practice questions but struggle to hold my concentration for Q 31-41 in any sim test . I have almost perfect scores in RC when I time nd practice randomly but today in my gmat prep-1 I got 8/14(6 incorrect RC), with the only 3 mistakes in the first 20 questions being Q6,7,8 of 1st passage :/
Also I made 11 mistakes in the last 21 questions in the V section.

Performance so far :
Princeton-1 01 Dec 590 (42/30)
MGMAT free- 13 Dec 620 (42/33)
MGMAT 1- 18 Dec 660 (45/35)
MGMAT 2- 24 Dec 610 (44/31)
MGMAT 3- 28 Dec 590 (44/29)

GMAT prep-1
31st DEC- 650(47/33)

I wish to get at least 700 on my GMAT scheduled on 20th Jan, How can I improve ?
Any final suggestions ?

In the coming 20 days I plan to cover(should this sentence be".....I have planned to cover ? YES i guess.)
1>FOR q - kaplan 800, og green supplement and 122 math tough problems from a file which I found on btg.
2>FOR v- extensive practice 4 hrs a day online, mostly SC as this is where I err in general.

Any thing else required ? Open to all suggestions.

Thanks in Advance
Pushkal