Oh, WWB, one thing I'd try is changing whatever hair removal/leaving method you're using. Either change how you remove hair (if you do) or stop removing it. That might well shift it.
(I've been thinking about your thrush problem, as the skin thrush I used to have used to drive me bonkers.)
Oh, and I had a fungicidal ointment from the GP which helped, but I preferred to avoid using it ...