The drop in grades is a potential red flag, as these schools are even more academically rigorous than where you are right now. Make sure to communicate the causes of the change in your academic performance in your applications. You have to convince admissions that you would thrive at their school, and your current performance is a blip.
If you have been going through more than the standard 2020 craziness, do not be stoic and silent about this in your application. Rather, be forthright (but not melodramatic) about your challenges. In order to be understanding, people have to understand.
Make the most of the ECs you have, and cast a wider net.
There are many schools that would love to have a bright, independent, intellectually engaged student like you, even without a daunting list of extracurriculars.
Some things to think about:
why are you applying?
what works best for you in class?
what kind of people do you want to be around?
If you are going to board, then the boarding atmosphere is very important to assess. How strict are you comfortable with? How casual?
If you’re open to participating in sports, you have some options. If you hate sports and loath gym, you might want to do some more research.