So sorry you had to go through this. I experience hyperventilating almost constantly when I'm anxious and some days are really hard. It makes me very lightheaded and confused..Occasionally I think this is it..now I'm going insane : ] I haven't found a way to stop it. Xanax didn't work for me..The only thing that I can do in such a situation is to retract to a quiet place (usually my room) and tell myself it will be ok..Some people do mindfulness exercises, eg they imagine a safe place in order to calm down. Also trying to take slow, deep breaths is helpful but I know that it isn't always easy to stop the hyperventilating cycle. Sometimes you can only wait until it passes. I haven't died or gone crazy so far so chances are I won't this time either : ] I hope you will get the breathing anxiety under control. hugs