I think the dr who saw was extremely unhelpful and totally out of order. She should have been more sensitive. It's never a waste of time if you're feeling unsafe or anything, and I think you should go to your normal dr as soon as possible.
I'm really sorry to hear you're having such flashbacks :( That must be really difficult. Just do your best to find coping mechanisms that work for you, and keep using them. I would try and get some sort of dr's note or at least try writing to someone high up in the college about your cat.
Here's some links which I hope will help:
Anxiety and panic: gaining control over how you're feeling
http://www.stresscenter.com/symptoms/
Five Ways to Calm Down.