Okay, okay, catching up, catching up.... uuuuuhhh
@Poshi: It may be the size difference between you and your partner. My bf is a whole lot taller than me, so it's common for me to be all willing and wanting and his entering still hurts no matter how horny I am... Unless I'm on my fertile days, tho it can hurt then still. It may be your partner's member shape or maybe his size is just too big?
Or, on extreme case, maybe it's vaginismus (aka vaginism)? I'm not entirely sure how it works, but it's mainly a mental block women get for various cases. Like used to be raped/molested or lived in condemnation of sexuality all her life... and since you mentioned your family is very conservative plus you feel discomfort very easily, I'd bet on a terrible mental block. So maybe visit a sexologist?
About orgasms tho, can't you come from at least clitoral stimulation?

Or mouth action? These are pretty strong, I can recommend
@River: Haha, foot cramps while on top, we all get that I guess

Positioning your feet on flex helps most of the times and don't switch even if it hurts, you'll get your cramp for sure then. How many orgasms I've ruined for myself only because I switched my feet to relaxed position and got cramps instantaneously. -.-