You might want to try using tea tree oil as a topical treatment (grapefruit extract or oregano oil can be alternatives if tea tree oil is not available), then use diluted apple cider vinegar as foot soak. You just have to be patient though because it can take months for you to notice the result. To make these remedies more potent, you can use an otc anti-fungal cream like ZeroFungus in conjunction with these herbal cures. Perhaps, it will make the treatment faster. I wish you luck in treating your nail fungal infection.