Just tell him this
Explain it
Make sure he understands that you like his existence and it isn't cuz you hate him specificallyAlso you just 'lost' attraction to men? How does that work….
But anyways yeah just explain it and be kind about it
I realized I don't like men. I liked he idea of it, and he was a sweet guy, so i went for it, but i just don't feel attracted to him, or to guys in general