What is wrong with my vagina?

This is the second or third time I've seen my doctor. He performs a pap and checks to see if I have any type of an infection and, I come back negative,  all the time std free and bacterial/yeast free! But I'm having so much pain and no one knows why. The doctor said he saw the irration.. What could this be? I'm losing my sex life and comfort! 
Please help!