I don't think it's sick or you're crazy or anything, I think you are lacking something in your life and like I said this obsession is filling a void for you. I also imagine scenarios with "my" guy in my head, like just lying together talking and kissing. He has taken my mind off a lot of bad stuff and that's a good thing, but i know when he meets someone I am going to be so crushed. I'm a lot older than you (and even him lol) as well, so it's really kind of strange in my case.