This should be your primary concern.
For a few very top ranked universities (Harvard, Princeton, MIT, Stanford,…), ECs are how they decide among a long list of applicants with nearly perfect GPAs and glowing letters of reference. With as many B’s as A’s, aiming at a few very top ranked universities is not realistic.
For pretty nearly every other university, your grades will be the most important part of your application. ECs are way, way less important. You can get into very good universities with no ECs at all, or with the ECs that you are already doing.
Taking 4 AP classes as a sophomore in high school almost certainly suggests that you are jumping ahead way, way too quickly. Slow down. Stop taking so many AP classes.
There are a lot of very good universities in the US. You do not need to attend a “top 10” or even “top 50” university to do very well in life. MIT graduates routinely work alongside U.Mass and UNH graduates and in most cases and in most careers no one cares where anyone got their degree. You also do not need to attend a “top 50” university for your bachelor’s degree to get into a highly ranked graduate program. I either know or used to know a lot of people who got their bachelor’s degree at universities ranked anywhere in the 50 to 150 range who then attended very highly ranked graduate programs (including Ivy League and “top 10” graduate programs).
However, this is all getting ahead of ourselves. For now you need to back off to take high school classes that you are ready to take. You probably should talk to your guidance counselor. Depending upon how your parents feel about this and how you get along with your parents you might want to have your guidance counselor recommend to your parents that you slow down in terms of which classes you are taking.
My daughters started crew either at the age you are now or at an older age. However, they were built for it (tall, with strong legs).