I've had foot nail fungus for more than a year I used medicines prescribed by my doctor but nothing has happened How to cure foot nail fungus?

Nail Fungus Cure? First off let me tell that you that "curing" fungus is a difficult thing to do. Much like a common cold, once it goes away, it can come back. There are some instances where oral antifungals (is that what your doctor prescribed for you?) will not eradicate the "fungus." If that is the case with you, the doctor should send out a sample of the nail to confirm that it is actually fungus.
Medications. There are a number of different medications that may be prescribed to treat toe nail fungus. The oral medications are often the strongest but can be more expensive & have more potential for side effects. I don't know how apt medical providers in Britain are to try that route. Would discuss further with your physician. There is a new medication that can be painted on nails that is an option too.