Men like the chase. It sounds corny, but it’s true, and if you sleep with them too soon you take the opportunity for them to chase you, away. Instead of making him feel like he won you over, you made it very easy for him and he isn’t interested any more. I’m sorry, but that’s what’s happened. The reality is guys want a woman who makes them work for it, and when you have sex too soon, they wonder if you do this all the time, and if they’re really special at all to you.
For future, wait. I don’t know how old you are, but it sounds like this is part of your learning curve in dating. As for this guy, I don’t think he’s interested in you except to have sex with. When a guy really likes you, he’ll want to date you, make you feel special, put you on a pedestal and show you off. I think you should accept that this didn’t work out, learn from it and move on to better relationships.
Let me know if you have any other questions.