What could this be? Burning sensation

I have this area between my labia majora and labia minora that burns a lot depending on how it’s touched. However, when I purposely run my fingers or nails on the skin to see where it is I can’t feel anything. It burns really bad at random times, like if my underwear is rubbing against it or I scratch the area. It can’t be razor burn cause I shaved two weeks ago and I never get razor burn anyway, I usually shave every week but I was afraid to do it this week because of how bad it burns. I can’t see anything though, I thought it was a rash or something but the skin looks normal. Any ideas?