Can you tell us more about your preparation?
--Which resources did you use, and how did you use them?
--How much of the OG did you complete, and did you time yourself as you did problems, keeping track of your times/answers?
--What were your study priorities? Did you have any weak areas identified?
Also, please tell us some more about the official test day.
--Did you finish on time?
--How many guesses did you make, and under what circumstances (e.g. guessed when stuck at a certain time, guessed because time running out, guessed on certain question types)?
--Don't tell us about them (please don't violate the confidentiality agreement), but were there any questions that stand out in your memory as either unusually tough or unusually easy? Those memorable questions might help you retrace your steps and figure out where you might have gone wrong.
One thing about your post really stands out to me:
Shirker
...and complete Verbal section without any difficulty…..
It's counterintuitive, but having no difficulty on an adaptive test can be a bad sign. Since the test adapts to you, you might have been making just enough errors on relatively easy questions that the algorithm didn't give you any hard questions.