I have rash around the bikini line it now spread to the side of my vagina cheeks, its itchy and raw and hot to touch n skin turned black what is it?

Don't know: Rashes are really impossible to diagnose over the computer, so seeing a dr for a visual examination would be your best bet. In the bikini line though, you may have shaved and that can cause an irritation and folliculitis like rash. Groin areas commonly get fungal infections too. But as stated, these are guesses only, see a dr for the answer and tx, best wishes.