How to gain certainty

I've been in a long-distance relationship with my partner for four years now. He’s living with friends about two and a half hours away, while I’m at home with my parents. I struggle with severe mental health issues and autism, which has affected my sex drive lately—I find myself lacking interest, while he seems to want it more than I can handle. When he visits, he tends to be quite insistent about sex, despite me communicating my struggles. This pressure creates a lot of anxiety around sexual activity, and we often end up fighting instead of enjoying our time together. I truly love him, but it feels like we’re both wanting aspects of each other that aren't attainable. I’m at a crossroads, uncertain whether this relationship is what I truly want or if I’m genuinely happy. I enjoy our time together when he’s not bringing up sex, but that happiness quickly turns into conflict. I’m dreading the thought of breaking up, yet I feel so confused. How do I determine the right path forward?