My doctor put me on Vancomycin for a month and a half because I had c-diff really bad. I was a full time graduate student at the time, and at my doctor's request, my school allowed me to complete the remaining of the semester as a fully remote student. Thank God!
There was no way I could attend classes having constant pain, diarrhea, and serious fatigue.

You will get better, it will take time, but you will definitely get better and regain your weight.