Hi Avigano,
The extra information that you've provided is quite useful, as it helps to define what went wrong on Test Day. In real basic terms, you took your CATs in such a way that you were NOT properly training to face the Official GMAT - so you were not ready to face it on Test Day.
Test Day is a rather specific 'event' - the details are specific and they matter, so you have to train as best as you can for all of them. The more realistic you can make your CATs, the more likely the score results are to be accurate. The more you deviate, the more "inflated" your scores can become - and that's what happened here. By skipping sections, taking the CATs at home, taking longer breaks, etc., you weren't properly training for the FULL GMAT 'experience.' Your Verbal score drop is easy to explain - when you took your CATs, you would start the Verbal section after about 1.5 hours of prior work (the Quant section and your extended break) - however, on Test Day, you didn't start the Verbal section until almost 3 hours had gone by. At that point, you were likely exhausted and would have probably found it difficult to focus.
Thankfully, this is a relatively easy set of problems to fix. The big question now is "how long will it take you to properly get 'used to' taking the full GMAT?" You'll certainly need a new set of practice CATs to work with and you have to put in the necessary time to train your brain (and body) for the FULL GMAT. You might also need to invest in some new GMAT training materials.
1) When are you planning to retake the GMAT?
GMAT assassins aren't born, they're made,
Rich