Diaper rash in the lady parts

As the tittle says.. FTM.. LO has a rash in the lady parts for over a month now. Have tried everything from aquaphor to desitin to the boudreaux butt paste and now we are doing Lotrimin AF. Nothing is working. Pediatrician seems to not be concerned. My deductible is high and since it’s the beginning of the year, each visit is about 128$. Had 3 visits about this rash already and no solutions. I’ll go again if it worsens but just looking for some mamma advice?