So sorry to hear about your fungus problem! I would go back to the vet again now that you know it is worse, maybe there is a pill that can help? I know for humans with ringworm topical treatment is tried first but pills exist for persistent ringworm.

Perhaps you can ask if there is food that might assist in recovery like yogurt - the l. acidophilus might help the body fight the fungus but I'm totally just guessing. In the meantime you'll just have to be very diligent with the cream and I can imagine that's not easy, how do you tell a dog not to lick certain spots?

Best of luck.