Again, not a Doctor here but here are my 2 cents:
1. I forgot to mention this, but the author of that book, Dr. Claire Weekes, is going to first ensure that you've gone to the Doctor so as to confirm that what you are feeling is indeed Panic/Anxiety related...and not something else. This is very important, so If you have not done this please go see your doctor.
2. Did the meds help? Yes. The Lexapro is a non-narcotic, seratonin re-uptake inhibitor. Personally, I had virtually no side effects and didn't feel any different when taking them. Downfall, they take up to 2-3 weeks for any results to be seen. Positive: It's non-narcotic! My doc also prescribed me Ativan for those nights when the symptoms were unbearable. I took those with caution and tried not to become very reliant on them. The Ativan will knock you out, don't plan on functioning much with these. I'm not saying avoid them, I think they do have their place, but use Caution.
Sucks that you have to feel panic, I know how aweful it can be...but hey, It did get the ball rolling on your Quit, and Quit is Good :)
Take care and keep that shit out of your mouth today.
CC