This Is Really Scaring Me. Help?

I am having some guy issues that are kind of scaring me. There is this guy who used to be a really good friend in elementary school and then moved. He ended up adding me on Facebook and we got to talking. After a while he kept on asking me for my number and wouldn't stop so I gave it to him(BIG mistake). After that he started texting me, but when he texted me he would text every two minutes if I didn't text him back right away. So I told him to stop and he still did it and I thought he was being a little bit controlling. He goes to a different school and I barely know him anymore so I told him to just leave me alone and to stop texting me.After that he FINALLY stopped. Now, his Facebook and Myspace statuses are always like, "You're stupid" Yadadadada... There's this girl he talks to that knows a lot about me, and I'm scared she's gonna like give him my address or something. He seems like a controlling person so I'm kind of scared of what he could do. My friends also tole me he's really obsessed with me. But, I don't like him, or barely know him! I'm just kind of freaking out and didn't know if anyone could calm me down or something.