Talk to Sexologist on Rash And White Pimples On Genital Area

I have been observing this rash for 10 days now I was told to keep it clean dry and airy for 2 weeks and let it blow over but it has made little to no difference at all. Also I am not taking any medication for this as of now. it's like big half moon rash that starts from my pubic area to my anal area also covering a little part of my left thigh I also have formed 3-4 small white pimples on my pubic area. It itches enough to wake up sometimes and I am very concerned regarding my next steps any recommendations please!