If my acceptance is rescinded, am I able to file an appeal?

I was accepted off the waitlist into the College of Science. However, I currently have a D+ in my AP Environmental course as my final grade. I had straight A’s first semester, but around March I fell extremely ill, was hospitalized twice, and have since been pulled out of school and I am now in a homebound program. This illness is the reason for my significant drop in grades and I’m concerned that my acceptance will be revoked. If this happens, is it possible to contact admissions and file an appeal, informing them of my situation? Alternatively, should I contact admissions beforehand? Thank you so much!