Why don’t I enjoy sex anymore? Someone please help! I’m so miserable

I use to always want to have sex but now I’m never in the mood for it and I’m only 21. This happened when I got off of birth control. I’m not even wet anymore and sex is uncomfortable and hurts. It feels like my boyfriend is too big. We had sex the other day, the first time in a month and it hurt. I don’t know what to do. This is making me so miserable. I don’t feel like myself. My periods are still irregular and I spot now, which I’ve never done before taking birth control. I’ll bleed for two days and then stop. Or wake up and have a little blood and that’s all