I'm glad you reached out, and I'm happy to help. The main question here is why you scored significantly lower on the verbal section on the real GMAT than you did on your most recent practice tests. Since nerves did not seem to be an issue, it's likely that some of your verbal weaknesses were exposed when you took the GMAT.
Scoring high on GMAT verbal tends to involve using logic and noticing key details. However, it is possible to get some verbal questions right by looking for patterns that you have already encountered in your preparation. Looking for patterns will not always work though, and if the patterns with which you are familiar don’t show up in the questions that you see on the actual GMAT, your verbal score will not be very high. So, one possible reason for the difference between your verbal scores on practice tests and your verbal score on the real GMAT is that in your preparation, you did not really learn to do what you have to do in order to score high on verbal. Rather, you picked up on some patterns that were effective in getting you relatively high scores on practice tests.
To hit your verbal score goal, you probably have to adjust the way that you have been preparing. You have to focus your preparation on developing skills, such as use of logic, that you can use to correctly answer GMAT verbal questions regardless of what verbal tricks the test presents. In order to develop those skills, you may need to slow way down in your verbal preparation, and analyze questions and answer choices until you clearly see the logic of questions. In other words, your preparation has to result in your clearly seeing what is going on in verbal questions.
Certainly, if you’d like more specific advice on how to improve your verbal skills, feel free to reach back out.