Hello,
Nail fungal infection is tough to treat and oral antifungals are often required. They are prescribed after assessing the liver functions. Since your liver function tests have come out normal, you can take the oral antifungal drugs but should take it under medical supervision.
In onychomycosis(nail fungal infection) nail plate can have a thickened, yellow, or black appearance. The nails can become rough and crumbly, or can separate from the nail bed.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Soak you nails for about 15 min in warm water with a cheap instant tea solution mixed in. Daily until fungus disappears. No side effects either. Tannic acid is the miracle worker.
I also want to say that my doctor did take a sample from my nail, had it tested and it came back positive for Onychomycosis.