Yeast rash solution?

As

I posted on here last week asking for suggestions to help with my sons rash. Well I ended up taking him to the doctor and she said it was a yeast rash and prescribed nystatin...after a week his rash kept spreading so she prescribed another ointment. She said it was aquaphor with a medicated powder in it, but again it’s not helping at all. His rash keeps getting worse. Before I tried all the rash creams I could get my hands on, I tried coconut oil, cornstarch, just using a cloth instead of wipes, airing his little butt out...I’m just lost at this point. We haven’t changed diapers brands because we had an issue with Huggies when he was a newborn that he reacted to so he’s been wearing pampers swaddles for the last 8 months...help please!