Welcome to the forums and thanks for starting this thread I'm really sorry to hear you're dealing with cyber bullying. The issue is a big one and you're definitely not alone.
Here is a link to some of ReachOut's articles on cyber bullying that might be helpful for you.
What kind of impact is it having on you? You say it's doing your head in, which is understandable! Can you explain a bit more what that means? Does anyone else know about the bullying and how you're feeling?