See simple thing that neet 2021 have not yet taken place that clearly means that you still have ample time for neet 2022. Thinking of taking drop from now itself is a wrong deci because this shows that even if your given 3–4 yrs you will not be able to. So I would suggest that you better start preparing from now itself with high energy till the exam of neet 2022 and once you have given your paper that is when you should take the decision of taking drop or not because that is when you actually know if you have done well or not.
And yes if you are preparing for neet 2022 then I would suggest that don’t waste time on classes as they are of no use its just a money making business, but still if you’re a student who can’t study on own and need someone’s constant guidance then yes you should join some classes. But as I said self study is best.
See any competitive exam can be cracked in just a year be it any even upsc. It’s just that you have to keep your mind so strong that no matter what happens you should always have confidence over your self. And you should always say that I’ll make it happen at any cost and not after two years but this year itself and I promise you trying keeping confidence on your self you will see results within days. Believe yourself…
All the best. Hope you got what you wanted and what I meant to say