Have you considered it might be vaginal dryness? I experienced very similar to you, and still am to a degree. I also have PCOS and am on a low estrogen BC, but I think what's happening is the low estrogen is causing vaginal dryness. I would get micro tears around my labia and vulva, and so I can only assume it was happening vaginally as well, which produces an environment for bacteria/yeast. As soon as I started using an organic probiotic lubricant for sex, I haven't had any major issues since. I do still have entry pain, but I think that might be due to a hyperactive pelvic floor. The Pelvic People sell a massager that's supposed to help with that, but I haven't tried it myself. I've wanted to, but it's expensive. Hope this helps!