You have choices, None of them quick, easy or guaranteed. Topical medications alone rarely work, especially if the nail has thickened at all. Oral terbinafine has its risks but the highest success rate. Laser treatment is safe, but isn't covered by insurance, so there's a large out of pocket expense.
Oral-topical-laser. Fungus can be treated with topical medication, oral antifungal medication and laser treatments. The topical medication has a 17% cure rate. The oral medication and laser treatments have a 80% cure rate.