Thank you everyone for sharing ideas on how to treat Teddybear's fungal problem. I've asked Dr Susanna Brida and she concurs that ACV is the safest and one of the best methods. She also agrees that the problem surfaced probably due to a dip in Teddybear's immunity.
Here's what Dr Susanna says:
I fully agree with what your vet said – it’s currently an immunity dip of which the little guy should be able to recover fairly soon!
Your apple cider treatment is by far the best that can be done (considering his age but ALSO generally for cats!) and together with just supporting his general recovery this health problem will soon be history.
Best wishes to little Teddy and you.
I've been dabbing ACV three times daily now, and I hope I'm not imagining things, but the spots look a little better (not so pinkish anymore). Teddy also enjoys the massage!