Dip in Senior year grades

Hello, I’m currently a senior (Asian Male applying as a public health major) who has just finished his first semester. Unfortunately this semester, I experienced a dip in grades due to some extenuating circumstances in addition to the added stress from the college admissions process. Previously, I had a 3.9 academic gpa unweighted and 4.7 academic gpa weighted, but this semester I have a 3.2 unweighted academic gpa and a 4.2 academic weighted gpa. I had only gotten 4 Bs in total coming in to my senior year, but now have 4 Bs in this semester alone. If I were to explain my circumstances in the additional comments section, would I still be considered competitive for schools such as Cornell, Rice, Emory, Tufts, Brown, USC, Vanderbilt, Case Western, and Dartmouth?

My classes and grades are as listed below:
AP Gov: B
AP Lit: A
IBHL Bio: B
NJROTC: A
Calc BC: B
AP Physics 1: B

My SAT score is 1550 with a 22 on the essay and I am a prospective national merit semifinalist. I also have an 800 on SAT Math II and a 780 on SAT Bio.

Furthermore, my ECs are pretty well rounded as I am the VP of the Speech and Debate Club, Commanding Officer of one of four 100-man companies in my NJROTC unit, a varsity swimmer, Vice President of the Politics club, Vice President of a volunteer club that donates shoes to the less fortunate, and a volunteer piano instructor at a music camp for the less fortunate.

Lastly, should I contact schools that I have already applied to about my extenuating circumstances and if so how? Would it be considered whining to report them?

In my opinion, instead of contacting the schools yourself, you should have your guidance counselor write an email or letter explaining your extenuating circumstances with you.

My counselor is already doing so. However, I am still curious as to whether or not I should as well.