To elaborate further, if this was a situation where you admired this girl from afar, or, were good friends with her and wished to progress to a relationship, then I'd suggest something similar to the advice Aureolin has kindly provided.
However, despite your infatuation, it seems like you live in fear of this girl and any attention you give her is wrongly interpreted as harassment. Even if you somehow move beyond that impasse, it's unlikely to provide the foundation of a healthy relationship. This is why, in my opinion, you need to walk away before it turns into something ugly.
RE: What's annoying you today? V2