Bad Senior Year Grade

Hi, I’m a senior finishing up the first semester. I applied RD to some top public universities (not UC though) with an instate advantage, but now I’m going to get a C+ in AP Calc AB first semester and it’s terrible and I’m freaked out. I’m taking several other college level classes with A’s in almost all of them except for 1 B+, and didn’t apply as anything Math related, but I can’t get over the fact I’ll be submitting my first C+ senior year in the midyear report. Math has always been my worst subject, but this is horrible and downright my worst grade.
For a little more context, my ACT score is a 33. The math score itself is decent, at 30, but oh well.
Help?

C is a little too low and will hurt. My rule of thumb is that as long as your GPA hasn’t dropped by more than 0.5, you’re fine, otherwise, you better start thinking about safeties. Also, you have to take everything in context to the schools you are applying to. A 33 ACT can be good or bad depending on school (actually it would never be bad, just slightly below average)

You don’t mention which schools you’ve applied to, so I can’t tell you with any precision if the C+ will hurt you or not. But at most colleges, one C+ in one class won’t keep you out, if the rest of your application is solid.