It sounds like you were seriously burned out and stressed. You also mention taking a practice test 2 days before the real thing. Were you also studying a ton in the last few days? Did you get a good night's sleep every night for the last few nights?
I'm guessing you studied a whole lot and also maybe didn't get enough rest.
The closer you get to the real test, the more you rest and the less you do. Don't take a practice test within 5 days of the real test - you just tire yourself out!
Also take a look at this article to identify what else might have gone wrong:
http://www.manhattangmat.com/blog/index ... ent-wrong/We want to figure out *everything* so that we know what to fix for the next time. Once we figure that out, we can set up a plan and also figure out how long that will likely take.
Also, use the below article to analyze your most recent MGMAT CAT:
http://www.manhattangmat.com/blog/index ... ice-tests/Then come back and tell us your analysis (not just the raw data - the actual analysis!). Also tell us any ways in which you deviated from official testing conditions on the practice test (skipping essays, taking longer breaks than allowed, seeing repeated questions, etc.).