What Causes Severely Itchy And Irritated Skin Around Vaginal Area?

I have been getting very itchy and irritated around my vaginal area. I have been tested for stds and nothing comes up. I tested positive for a bacterial infection which they gave me medicine for but it is coming back. Also, whenever I sneeze while I am sitting in a certain position, I get a sharp pain in my ovary (or both). I have been to the gynecologist multiple times and nothing has come up, even in an ultrasound. Help!