Need Help. Hamster With Pre-Existing Ringworm

I wonder if anyone can help/ provide consolation. I have a Syrian hamster and he came to me with a case of ringworm (identified post adoption).

The situation is, the vet has prescribed him some cream. But he's getting really stressed and keeps dodging the treatment (on his snout).

I've spoken with the vet who says because of his size other treatments would be too strong.

Whilst inspecting him tonight, I noticed more bald spots on his body. I don't like to do anything drastic, but the thoughts are going through my head right now as to whether the kindest thing to do is to let him sleep.

I'm just torn because he's the kindest and silliest thing and apart from the ringworm nothing is wrong. What would you do?