For most of my life I have enjoyed and been great with people, but lately I've been having sudden anxiety attacks when I'm around others for what seems to be less than 2 hours. I find myself avoiding parties at all costs because around the two hour mark I start to feel shaky, scared and like I'm going to throw up. I feel like an odd sort of Cinderella, because when the clock strikes 120 min, I get a sudden feeling of anxiety and I need to leave immediately. Is there any treatment or simple diagnosis? I've never had anything like this before.