I Was Diagnosed With C-diff, Prescribed Flagyl And My Last

I was diagnosed with C-diff, prescribed Flagyl and my last labs were negative, however, my tongue and mouth has had a yeast infection that Diflcan has not helped. I also have serious blood issues, iron and ferritin down to zero, hemoglobin is 9.2 and I have zero energy! I have had Melanoma in the past year, two incisions got clean margins but of course I am afraid of it returning. Do you think any of my symptoms could be cancer related?