I can't get off from sex or masturbation. Any advice?

I've been having sex with this guy for a while now, and I hardly even feel anything down there. Half of the time it even hurts, but I've been having sex for a while now. Some days it doesn't hurt, but most days it does. Shouldn't it have stopped by now? He's my first and only, so I don't know, but masturbation doesn't do anything for me either. I hardly feel it, and when I do feel it, it hurts. I don't know what to do anymore. My guy seems to feel self-conscious, but I think it's just me. I don't understand what's wrong with me. Any advice to try and make it feel better? I've tried different positions, and they feel kind of good, but not as amazing as what others describe. It's just sort of dull and very very slightly pleasant.