How to prevent a rash. I have developed one due to work which I am required to ride a bike.?

I have developed a rash around my l area. I went to the doc and she said that it was a fungal infection. I've been using the treatment and completed all of the cream. The rash was gone for a while but now it has come back. Is there anything that I can do to prevent the infection? Anything I can wear or put on to keep the rash from getting worse?