Hi,
I am giving my GMAT test on the 21st of February next year. I just took a mock CAT(GMAT prep) and got a score of 620. I need your tips on improving my score, with just 55 days to go. My breakup score on the mock test is as follows, Q40, V35. One thing I noticed in the mock test is that I didnt have enough time to finish off the questions. I had to guess atleast 7 quant questions in the end(and got all 7 wrong

). In verbal I was a bit okay, I had to guess only the last 2 and got one right. I couldn't concentrate hard enough on the verbal questions, all my mistakes when i reviewed them were very silly. I really thought that I could've got most of them correct.
How do I improve my speed and concentration levels for the entire 4 hours?
I have gone through almost all the topics in both Quant and Verbal. i used
manhattan books for verbal and for Quant, The GMAT Club math book helped me and I also took help of IMS CAT materials.
Also I need to know the resources which will help me to improve my score by atleast 80 points. Please respond. Waiting eagerly for some advice.
Thanks,
Dewakar1165.