Hello,
From the symptoms it looks like fungal
nail infection or trauma skin. An infection of
nail fungus occurs when fungi infect one or
more of your nails. Nail fungus can be difficult to treat, and repeated infections are common. Over-the-counter antifungal nail creams and ointments are available, but they aren't very effective. You need to get a KOH examination and fungal culture of the nail scrapings done and then oral antifungals prescribed.