I feel like I've read a ton of books about panic disorder, etc, but this one was short, sweet, and almost humorously written. It was light enough for me to pick up and read tonight (sometimes panic books actually make me anxious).
It's called The Panic Diaries, The Frightful Sometimes Hilarious Truth about Panic Attacks. By Jeanne Jordan and Julie Pedersen.
Anyway, if you ever stumble upon it at the library (not sure I'd buy it), definitely pick it up :)