How do I break up with my boyfriend?

Hi...? I've been dating this guy for a couple weeks but I... might... want to end it. Problem is he's really sweet and i've never broken up with anyone before. He's kind of smothering me and he calls me every day after school. I get made fun of because he's dyslexic so he has to be in special ed and I feel bad saying this but he's kind of embaring... he makes a gun formation with his hand and shoots people and he has this really annoying catch phrase "I C U" and it drives me nuts! And if he calls me but I don't answer he'll leave a message that just says "I C U I C U I C U" instead of actually talking. I really, really like him though but I don't know whether to ignore it, tell him it's over, or tell him to back off a bit. My real question I want YOU to answer is what should I say if i want to break up with him AND how to tell him to back off. AND WHICH ONE DO I PICK!?