You know, this isn't all that uncommon - the clock and the test-day pressure definitely play a pretty big role in almost everyone's performance. A few things you can do to help counteract this on your next test:
1) Take practice tests. It sounds like you feel comfortable with the content and strategy but need to simulate those timed conditions and the overall stamina of taking the test in one fell swoop. Your study to this point will help, but for "putting it all together" you should really get to work under test-like conditions.
2) Practice the verbal section while tired. One thing a lot of people underestimate is how much of a toll that whole test day takes on your ability to focus on the verbal section, which comes last. If you were acing SC and CR questions and focusing on (and enjoying) RC passages when you did verbal practice after sleeping in on a Sunday morning, now it's time to make sure you do some math review before you start verbal or you do verbal homework at the end of a long workday. This will force you to use strategy to stay focused and attentive.
3) Check whether you're too reliant on note-taking for RC and CR. If you're taking too many notes, that's labor-intensive and can make the clock a factor and weigh on your stamina a little bit. See if you can do a verbal practice test and use 2/3 as much scratch paper as you usually do.
Brian Galvin
GMAT Instructor
Chief Academic Officer
Veritas Prep
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