What should I do?

At the beginning of december I started talking to a guy that goes to my college, this was during christmas break. We spoke every single day. Then when we came back to college we started hanging out together watching tv shows and movies together. Then the other night we were both drunk and we slept together. This has now caused him to step away a little bit and he doesnt reply to me as quickly as he did before this happened. He told me that he thinks its best if we just be friends. But I really like him, and I want to try and forget about what happened as I dont want to lose his friendship. I have no idea what to do as I really like this guy and I want to try and make something work... He also hasnt been responding to my messages as quickly as he did a few days ago as he use to reply straightaway whilst now he doesnt. Is there anything I can do that will make him want to talk to me like he use to?

What do I do?