Ellipses - my heart goes out to your daughter and you. Panic/anxiety attacs can be terryfiyng - I have been that route!

My first instinct tells me not to cut her ties with the school, do not shelter her at home - this will do nothing to cure her anxiety, it will just prolong the process of getting better.

I stopped on this sentence in your post "According to others, my daughter was not an instigator". Can you devoulge more? Am I reading more than necessary into your post?
I have also re-read your initial posting on this thread and it tells me that there might be other issues with your daughter.
Could she be depressed? Anxiety frequently takes off from depression. Did you think about having a frank conversation with a councellor?