I am wondering if you are breathing correctly when you say you are breathing deeply to control your attacks. I didnt breathe correctly, and it made all the symptoms worse. Once i learned the proper diphragmatic breathing, I didnt get to the point of feeling like I was going to pass out. When breathing properly - your belly should be moving alot more than your chest. Remember watching a newborn breathe ? Their little tummies go in and out, while their chest barely moves.......thats the way we should always breathe. If you are "gulping", or if your chest rises and falls more than your belly, or your shoulders move up and down while breathing, you are actually making yourself worse. WHen you breath wrong, it is hyperventilating - which can lead to passing out. I have known several people who WANT to pass out to stop their panic , saying when they come too - they are no longer panicked. Whew - I wouldnt wish that on anyone !

Another thought is vertigo. If the room actually felt sideways or upside down, that could be a possibility . (My Mom is going thru incapacitating vertigo right now and it is horrendous). I think I would talk to your Dr. and also, be sure that you are doing the breathing techniques corrrecly.

Good luck ! I hope you never have an attack that bad again.