Pain during sex

So I’ve noticed that I have pain during sex in 2 positions in particular. One is backshots. It’s absolutely horrifying and hurts really bad no matter what , I’ve never been able to take backshots with any of my partners. Another painful position is when my legs are above my head or over his shoulders , doesn’t hurt as bad as backshots but it hurts , I’m pretty comfortable on my side and missionary. Is there something wrong w me on the inside or can I just not take dick??