At the outset, we are glad to come across somebody who hasn't given up yet and we hope it stays in the same way up until you score your target GMAT score. If there is at least one person who has done something, it only means you can do it too.
Let us analyze !
We would suggest you to ask yourself the following:

(1)Is your performance without a timer and with a timer different?

(2)Are your basics/fundamentals so strong that you no longer need to go back to the books /videos even when you are stuck at a certain question?

(3)Do you have a habit to observe solutions(video/book) the minute you are stuck?

(4) Do you have a tendency to consciously/sub consciously "avoid" advanced questions?

(5)Have you analyzed the errors in OG and mocks well enough that you are confident of not making an error if such a question comes in your paper?

(6)Do you have your notes and flash cards ready?

(7)Have you understood the concepts and internalized them using questions and solving them without resorting to solutions?

(8)And finally have you revised enough and feel completely confident before you take the test.

If any of these questions can open up a new perspective, please analyze and fix that loop hole.
Have a mentor who can guide you and assist you in recognizing, assessing the intensity and fixing any weak end that may so exist.
We also suggest to have your ESR analyzed using professional help. That may assist gaining in further clarity.
We suggest you to take immediate steps, given you have your paper on 11thJan.

Pls feel free to jot down your worries.
We are with you in this journey!
We would love to see you with a score that you have set for yourself. You have put in a good amount of effort, time and money already and must give it a full shot to reach your goal!
We wish you all the best !
And we would love to hear back if you have an input/doubt.