VARC HELP NEEDED !!

scoring 30+ marks prove that your reading comprehension is completely intact. . defining you ability with just 2 low mock score isn't justifiable, this sudden drop isn't a loss of comprehension. it may be of different reasons such as familiarity with the passage/article , time management or RC selection
from now onwards, try to read different genres to get familiarity with the passage, do proper analysis after every sectional i.e use optional elimination method to eliminate options.
additional you can practice more on VA, this make your whole varc score to add up.

If you have given several of the mocks and are still not able to see the improvements, then the only possible mistake is that you are not analyzing enough. You are maybe just going through the questions after completing the mocks, but I would recommend that you give 2-3 days to analyze the mocks by understanding each type of question and your regular mistakes in all your mocks, and try to avoid them. Good luck; hope it will help