Priority change

I met this person last most it was kind of last minute thing. We both had great chemistry at the time I didnt mind just a causal sexual thing with him. But now I feel completely different and I really dont want that anymore. He still messages me all the time wanting to meet up we also live at least an hour away. I want to tell him that I am no longer interested but I also hope he doesn't feel rejected since I changed my mind. Should I just tell him? Because I also dont want to ghost or lead him on.