Not horny

Please can someone help me

Me and my partner have been arguing for month because I’m never horny. I’m never really feeling it, I can’t remember the last time I was actually horny...ever since being with him I’ve had pain everytime we have sex and he knows it, but he does try and help but it really does hurt sometimes. I’ve had scans but nothing shows up. Is there anyway I can be more horny or actually want it? Anything will help

Thank you