Im pretty extroverted, so i cant relate on that level but I can say that if you were to go out and confront the girl and/or her friends about that crap they might stop. Or is it possible to leave when her friends are over? That'd kind of be running away from the problem but if you dont/cant deal with the stress right now, you could do that. Maybe go down to a coffee shop or something. You might meet some people you like in the process.