what happened to my sex drive?

I used to have a really high sex drive. I would masterbate a lot and when we would have sex it was AMAZING. I've been with my current partner about a year and a half, we were together in 2013 but broke up and he's the guy I lost my virginity to (sex was also great then). I started to notice the sex got different several months after getting back together last year. I started taking birth control (something similar to Yasmin, munlea) around that time also) and we Simply used condoms/pull out method before. But since then I feel like I've had no libido. Sex usually hurts me - I struggle to get wet unless it's been a while since we've had sex, and I went to the doctors about it who could not notice anything physical on my vagina which may have been causing the discomfort. I started to wonder whether I had vaginismus as I do tend to tense before penetration, but I wonder if this is just because I'm anticipating the pain! I wonder if I have a lesion because if we try to have sex again in the same day, something will feel sore around the opening, even a finger will hurt. The doctor prescribed me some sort of lube but I found that it just stung me and didn't help all that much, just got too messy. I feel sad because I used to love sex with my bf and it's affecting him as well, like he feels like he can't turn me on. I'm still attracted