How Should Vaginal Pain, Vulva Itching, Soreness And Redness Be Treated?

For approx 3 years I've been suffering from an intensely deep pain in my vagina. I've also suffered from symptoms of redness, itching and soreness of the vulva. I've been tested for every STD, BV and yeast infections all of which came back negative. About a year ago i was referred to a gynecologist who performed another swab and found streptococcus milleri present. She prescribed me a course of penicillin but the symptoms remained and are still ongoing. I was never re-tested to see if the strep was gone, just sent back to my doctor who was at a loss. Please can you advise? Many thanks