As per the symptoms it seems that you are suffering from some sort of fungal infection
.The fungal infection may cause such symptoms in you.
You should have the physical examination done by dermatologist/doctor to know the cause and start the treatment accordingly.
It may take a few weeks for the skin lession to go off completely.
The broadspectrum antifungal ointments like ketoconazole
may be tried.In some cases the oral antifungal
may be used as well.
You should also get tested for diabetes and rule out immunocompromised state.The genital hygiene should also be done and avoid sharing towels.