What Irritation And Burning In Vagina?

I had a uti that turn into the worse yeast infection for 8 weeks I tried many tubes of monistat then finally Dr. gave me diflucan but didn't work. Then gave me a stronger cream that seemed to work but I still had discomfort. Dr. said yeast was gone but that the skin is thin and gave me a steroid cream. The cream seemed to help the first few days then stopped. my vaginal area burns all the time and more so in the late afternoon. I try to drink lots of liquids but the output is minimal, or so it seems because I get a little relief if I pass a good amount of water. I have not had sex in 3 months since this started. What is causing this constant irritation and burning. It feels as if my vaginal area is really dry especially near the urethra area so I started using vaseline to keep it moisturized.