What is wrong with me?

My SO and I have been together 8 years, after so long our sex life has slightly dwindled. At first it was semi-normal like any relationship. But about 4 years in we went through some hardships where he lost my trust, he didn’t physically cheat but i think it was only because i caught on before it got there, we worked through it and managed to move on. I hadn’t realized but after that I noticed I was no longer sexually attracted to him. I love this man sooo much and I have chosen to stay because I feel like he still completes me and makes me happy. I don’t understand how that can be but I can’t stand him touching me or having sex with him. It’s like my mind wants it but my body disagrees. Im confused. I know I don’t want anyone else, I don’t find myself attracted to anyone else so how can this work? I feel horrible because we hardly have sex anymore and I know he has been patient about it but for how much longer? What is wrong with me?