You're not done with those books yet - there's likely a lot more that you can learn.
You likely also need to do a lot of work with timing and decision-making on the test - most people at your stage do.
First, read these two articles:
http://tinyurl.com/executivereasoninghttp://tinyurl.com/2ndlevelofgmathttp://www.beatthegmat.com/mba/2015/07/ ... s-say-whatThink about how what you've been doing does and doesn't match up with that and how you may need to change your approach accordingly.
Then, use the below to analyze your most recent MPrep CATs (this should take you a minimum of 1 hour):
http://tinyurl.com/analyzeyourcatsBased on all of that, figure out your strengths and weaknesses as well as any ideas you have for what you think you should do. Then come back here and tell us; we'll tell you whether we agree and advise you further. (Note: do share an analysis with us, not just the raw data. Your analysis should include a discussion of your buckets - you'll understand what that means when you read the last article. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)
You may also want to look at this:
https://www.manhattanprep.com/gmat/blog ... our-score/Finally, if you feel that yout self-study hasn't been as effective as you would like, you may want to look into taking a class. I'm not saying that everyone should do this - it's just one possibility to consider if you find that self-study isn't getting you close to where you want to be.