Tessa,
I am sorry that you find yourself in a place where you have to be in the same proximity of a person that makes you so uncomfortable. I don't know what to say as I believe that you know all the "tools" that can be used. Sometimes there isn't a way to set boundaries, especially when another person just ignores them, and I don't know what a person does in those circumstances.
I hope that by being away from the situation that you can find some peace and a way to reel in the symptoms. Leaving the situation is the best thing you can do, and maybe when things settle down you can find a way to prevent finding yourself in a similar situation.
Wishing you peace.
(((Hugs)))
Debbie