How will one bad semester affect my admissions chances?

I know this is early on in the current semester. Still, I went from a 4.0 GPA in all Honors/Advanced courses, including one IB, which is the only one offered for my grade that I qualified to take, to taking those same courses but doing significantly worse. I have gotten C's on all but one of my tests/quizzes so far, with one B on a chemistry test. I am trying to find out the issue, but I think it could be a mix of things. Mainly lack of mental reassurance and health, as well as trying new medications for my ADHD. I just feel like I am super confident at first when I'm done studying, but when I get to the assessments, my mind just goes blank. I was wondering if anyone had recommendations on what to do to help my current situation, and B. How will this affect my admissions chances for getting low-high B's (B- through B+) in 3-4 of my classes? For reference, I am a sophomore in high school, my one honors is Economics/Government, and my one IB is Physics 1A. The rest are advanced. I am also doing double science this year.