Ladies only ~i have a rash the Dr's says is a fungus~gives me a cream~nyastitin?

The rash is under my belly where i am very fat~now i called dr he was off~so nurses called in my refill too late rash turned to blister~does anyone know how to heal this a cheaper way?the rash is under belly fat gets no air~i have a gauze on it with peroxide til i see the dr later today~but wonder is there an easier cheaper way to fix this problem~until i loose this menopause fat that just went there~ please help!