It does sound like a plantar's wart. My sister had one that didn't respond to the patches. She had to have it cut out.
sound like a wart to me. i had the same thing on my hand i used dr scholls wart freezing treatment and it went away and stayed away. you can get it at any grocery store its very inexpenssive and easy to use and some warts depending on size and location will go away with just one treatment
Sounds like a fungus,ask your GP to refer you to a dermatologist