I also want to reply about MIT. I’m concerned not only about the number of B’s overall, and the number in STEM, but also the fact that you say you got a B in AB Calc and in Honors Chem. Both of those courses are known to demand what is essentially cooperation with new ways of solving problems, and perhaps good student skills in general. This would be a red flag for me, despite an A in BC Calc.
My kids got into MIT, but one of them did not get into Stanford. Stanford seems not only competitive but weirdly random in ways I have never understood. As a HS teacher for almost 30 years, I saw kids get into Stanford that really surprised me, and some rejected that really surprised me. I think the athletics could open a route to Stanford, but that will not happen for MIT.
Also, I don’t exactly know what Computational Biology is, but are you sure that major even exists at MIT? It’s true that any STEM major will be world-class at MIT (or Stanford) - but it will also be great at many, many other colleges out there. As someone else asked, are you making a nice list of likelies that you might want advice on?