I've read half of a sentence so far. Before I read anything else: stop taking so many CATs. Seriously - you're wasting study time and a scarce resource.
Read this:
https://www.manhattangmat.com/blog/inde ... many-cats/I am unable to finish the test (both Quant and Verbal) on time
This is why your scores have been fluctuating. The more you mess up the timing, the more your score is going to drop.
Unless you fix the underlying problem, you may have the same issue on the real test. This is not something that can be fixed in one week, unfortunately - it typically takes people 4 to 6 weeks to fully address serious timing issues.
If your test is within one week, then you can't reschedule without having to pay the whole $250 fee. In that case, I'd say go ahead and take the test. If your final score is more than 100 points below your goal, cancel the score at the end of the test. Otherwise, accept the score (and plan to re-take if it is not as high as you want).
I would also highlight that I am guy that uses proper equations and methodical ways to solve quant question, which definitely slows me down.
So you already know part of the answer. :) You're going to have to make a major mindset shift - and that is likely to take several weeks to a month to master. (But go with it if your test is within a week - hope for the best but know that you have a plan if the best doesn't come to pass.)
Read this (right now):
https://www.manhattangmat.com/blog/inde ... lly-tests/Has this been your approach to the test and to your studies? (I know it hasn't from what you've written so far. :) Read that article every day for the next week, two weeks, however long it takes to internalize the message.
Next, every 99th percentile test taker will tell you that we wouldn't dream of taking the quant section without the awesome shortcuts that allow us to pick our own real numbers or work backwards from the answers or estimate or whatever. That stuff doesn't just save us time (sometimes it doesn't save any time) - it saves something much more important: mental energy.
You can't take a nearly 4-hour long test without hitting mental fatigue along the way. The more you can conserve your mental energy, the better you're going to do in the end.
Okay, next, read this:
http://www.manhattangmat.com/blog/index ... -the-gmat/And then these two articles on how to study:
http://www.manhattangmat.com/blog/index ... -to-do-it/http://www.manhattangmat.com/blog/index ... nt-part-1/And start doing what they all say, today!
If you'd like more specific study advice, use the below to analyze your most recent MGMAT CAT (this should take you a minimum of 1 hour):
http://tinyurl.com/analyzeyourcatsBased on that plus the previous articles, figure out your strengths and weaknesses as well as 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. 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!)