My kid graduated from HMC a couple years ago, and it is definitely stressful academically. I think it is especially hard for students used to getting all As or close to it in HS, and to hit the workload and grade deflation is very tough. You are in the heart of the Core right now, and past the pass/fail semester, which is hardest period for most students. If you are in season for your sport, that is even more stress.
Quite a few students take a semester or two off, and some transfer. If you have to take a bit of time off after this semester before coming back, or take a break and then transfer, that is fine! Mudd is not the place for everyone, and you can definitely still finish college and have a STEM career from another school. In the long run, if you take a gap year next year and apply to transfer, you’ll be fine.
My kid stuck it out in the face of barely passing some of her classes, but the 2nd and 3rd semesters were especially stressful. She was in the bottom half of her class for sure at graduation, but had options open to her for employment and grad school when she was done.
Mudd administration is concerned about students in your position. Talk to your proctor or a res life dean about it, and figure out who to see about maybe withdrawing from a class to lighten your load for the rest of the semester. And take to heart that a C is an okay grade at Mudd, and in a pinch, “D is for done”. My kid had a smattering of Cs on her transcript for sure, and she worked her tail off for them. Dean’s List at Mudd is a 3.0 or better, and my kid definitely did not make it every semester.
Regarding the 18.5 credits — maybe you have a couple of half credit classes that are really intended to shore up/ support areas where you aren’t as strong? My D had some of those. But I agree, the small slices of lots of subjects during core adds stress for sure. That part gets better after next semester. If you decide to return in the fall or after a break, work with your advisor to keep the credit load reasonable, especially during your sports season. Do not do summer math given how you are feeling (you might feel pushed to do that, but my kid didn’t — she desperately needed an academic break the first summer).
So… ask your proctor and res life dean for help. See about withdrawing or dropping a class. Figure out this summer whether you want to come back in the fall, or take a break, or take a gap year & transfer. All of those are solid options. Good luck - feel free to PM me if you want to.