Amazing to ouch!

Hi everyone. First post on here. I have been with my now fiancé for 6 years now. Sex has been amazing since our move back in May. For a few years now though things start out amazing but by the end (especially in missionary) it feels like sandpaper. I'm on the pill and use a condom. I have tried a couple different lubes but find that the irritation is worse. I also feel like it is worse if we start with a lot of foreplay. When I'm on top I don't notice it as much, if at all. Any ideas?? Thanks