Not able to get good score in GMAT Verbal

Hi,

I appeared twice in last two months for GMAT.

In my first attempt my score was 570

Quant. 49

Verbal 20

Second Attempt Score was 580

Quant. 44

Verbal 25

In between these two tests I tried alot to improve my verbal. I did alot of verbal material, but unfortunately there is no improvement.

I have gone through OG 11 so many times that now i remember all the answers.

I feel that I have improved alot on Sentence Corrections, but I am not able to do good in RC and CR.

I am from non native english background. :cry:

Can someone guide me what should I do to improve my verbal score?

Bobby