I need advice...

Sorry for not posting much: it's the first week of school, and I already have a good bit of homework. I'm actually taking a break from it right now.

So there's this guy. Not mentioning any names. But he won't leave me alone. And he's starting to get creepy. He called me nearly every day over the summer: we hardly even talked. He emails me constantly and gets ticked off if I don't respond as soon as he'd like. He follows me around school if he sees me. He gets ticked off if I don't tell him where I'm sitting for lunch. And now, he wants to share my locker.

Stupidly, I said sure. I'm going to take it back now, but he said that he was going to try to find me tomorrow morning.

The thing is...He used to be one of my friends. A good friend. Now, he's just scaring me. I want to get away from him. But I don't know how: whenever I try, he always finds me. Like the other day: I sat somewhere with two other friends of mine named Josh and Brandon. This guy FINDS ME and sits next to me anyway, asking me why I didn't tell him where I was sitting. The next day, I came in with Josh. The guy saw us, so I asked Josh to sit between us. He said yes, but after the lunch period was nearly over, the guy moved to sit across from me. The day before that, he grabbed my thigh. I hit him. Not very hard: he's confusing me. I thought he was my friend...

Now, he's just being a creep.

What should I do? I've tried avoiding him: it hasn't worked. I don't have a mean bone in my body: no matter how much I dislike him, I can't be mean to him. Should I just get to the point that I hate him and don't care? I don't know...

I wish he'd just go away.

Oh, and yes: this is the same guy that I yelled at in the middle of Wal-Mart.

He's really pissing me off...But I've never had to handle anything like this before...