After many years of being told my vaginal and vulvar pain following sex was either a yeast infection or all in my head, I finally found a "cure".
Through an internet search I found boric acid suppositories, and for the first time in years I can have sex without worrying I'll hurt for a month afterward!
Apparently I'm very sensitive to changes in Ph, including the kind that happens following intercourse. Yeast infection meds don't work or make it worse, but treatment with the boric acid has made all the difference. I now keep a minimum of 2 packages on hand...I buy the Vitanica brand "Yeast Arrest" from Vitamin Life.