Yes, your entire grade rests on however many questions there were on the Physics AP. Many kids, including my S, having no access to a world-class university and doing related research there, got 5s on both portions. Do I think your 4s in mech and bio, and your 770 on the math SAT (which MIT doesn’t use anymore) are what got you deferred? No. But given how easy it is for a gifted math/science student to get 800s and 5s on these exams, plus that you didn’t have great grades despite having access to world class labs and working with brilliant minds, for me, a picture emerges. Either you didn’t work hard enough to master the material or you aren’t naturally gifted enough to intuitively grasp the material. (Remember, no other country has holistic review; you ace the exams or you don’t get in).
Had you presented the same app but were a kid with no connections to Columbia, maybe you get in. Because you wouldn’t have been handed those research oops on a silver plater; you would have had to stand out and network to get those opportunities. But, that hypothetical student would still have the grade issue, and lack of ECs until 11th grade.
I think you’re lucky you got deferred and it was only because your dad is faculty. You need to apply yourself, 100%, to your studies and ace your classes. If you don’t get in, you should go to a SUNY, ace your classes and do research unrelated to Columbia. Be 1st author on that paper. Prove yourself unrelated to your father. And then transfer. This is a great learning experience related to understanding your privilege. I think if you own what happened (not try to justify it - so few questions/covid/only got serious toward end of HS), you’ll see that the students who were accepted worked extremely hard for all 4 yrs of HS, without the undeniably amazing access you had, and earned that acceptance. You want to earn yours too. You have a great future ahead of you if you do.