Not interested....

This guy is so sweet to me and treats me like a queen even tho we're not together... I'm just not interested and idk why I'm not but I'm not. I've tried explaining it to him but he won't take no for an answer. It's starting to make me where I don't want to talk to anyone no matter who they are and I just want to turn my phone off and stay in bed all day... I'm not sure what else to do to make him stop or understand that I'm not interested.