Yeah I was thinking the same thing as Xiggi when I was reading your post. I would not have guessed that you are an international applicant based on your writing!
Let me just throw 2 things out there, @dialga2014, one to maybe make you feel a bit better and the other to offer some suggestions on improving your RC ability.
I am a tutor and I have always scored a perfect score on the CR section when I have taken it as an adult, but I was very, very far from a perfect score when I was in HS. My verbal score was pretty mediocre actually. Looking back on it, I can identify 2 things. One, I really didn’t understand the nature of “Verbal” questions on standardized tests and in particular the fact that they are completely unambiguous, black-and-white, and that there is one definitely right answer and 4 definitely wrong answers (I actually posted about this on the forum very recently). But the other thing looking back is that I just didn’t have very good reading ability. And part of that was that I was never taught how to read critically and actively - this almost got me in deep trouble in college because I went to a very competitive school and I chose to study History of all things, and most of the other students did know how to read critically. So I struggled a little at first until I realized why and then once I learned to read in the way that I needed to things changed for me completely. When I took the GRE and the GMAT after college I expected that my Math scores would be much higher than my Verbal scores since that’s the way it was on the SAT, but I found that percentile-wise I was equal or better on the Verbal sections - this was an absolute shock to me!!! So this is all to say that it may be that you have not necessarily been taught how to read critically, especially with non-fiction writing (I have found that the overwhelming majority of students have not). But all is not lost because that is a skill that you can acquire and it may be that in the future you would be able to go back to the SAT and find that the RC feels much, much easier and that you would essentially dominate it because you have become such a better reader.
Secondly, I have to really applaud you for wanting to improve your reading ability given that you are done with the SAT. In my opinion being a strong reader is crucial for success in college and in life in general, so it is a very worthy goal. With that in mind, let me offer some suggestions. In terms of books that teach how to read critically, there may be better books outside of the SAT world that really teach this, but within the test prep space (and even including the GMAT, GRE, and ACT space) the one that best does it in my opinion is Erica Meltzer’s The Critical Reader. Maybe you have already used the book, but she does a very good job of explaining how to read for purpose, function, and attitude, a key skill in reading critically.
I also recently started a blog series on my website (I don’t think I can post a link, but you can probably find it by googling my username or you can just pm me offline) that is aimed at helping people learn how to read critically. The main goal is for the purposes of the SAT, but I also want to just help people become better readers and I especially want them to understand how reading critically is important for the reading that you will do in college and in the real world more generally. There is only one example up there now (I plan to add new posts as often as I can), but essentially I take an article or passage from the real world (an op-ed piece, an article from a scholarly publication, etc.) and then ask some questions about it and then in a follow-up post I offer some commentary on the piece and on the questions that I posed. Feel free to take a look.
In fact I considered posting about this on the forum, but I wasn’t sure if there would be interest in it. If people think that it would be helpful I could do it, but I don’t think I can post the same content since google will probably punish me for that! and I am also not sure if I am allowed to post the links to the articles in the forum (not sure what the rules are for that)? If some forum members think it would be helpful and if I am allowed to post links to the passages then maybe I could write some separate posts just for the forum so as not to duplicate content.