Daughter with a fungus on her finger

My daughter hurt her thumb just above her thumbnail about  a month ago and now has what our pediatrician has diagnosed as a fungal infrection.  At first he told us to put an over-the-counter fungal medicine for athlete's foot on her finger four to six times a day, but it grew farther down the "pad" of her finger and down the side of her thumbnail.  It wasn't originally, and for three weeks, under her nail.  It is not.  The infection has only gotten worse and is now growing down under her thumbnail and pulling the nail away from the nailbed.  Then, as were are out-of-town, I called the pediatrician and was prescribed a stronger medication that we got from a pharmacy. We were to use that medication twice a day and have done so religiously.  The infection has only gotten worse and seems to be causing inflammation of her thumb and deforming the shape of her thumb.

What shall we do????  I can't just let the infection destroy my daughter's finger but no one her or at home seems to know what to do with it???