Bad Midyear Report? Are my chances ruined?

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?