Hi Wryter,
I'm sorry that your anxiety is giving you a hard time. It's just a 'simple' tool, but I find it a very helpful and powerful... meditation. It helped me a lot to get rid or to decrease anxiety. When doing it regularly it works for a long period of time even if you stop it after a while. If you would like to start it, there's a 21 day meditation challenge you can enroll to (it started on Monday), it's organized by Deepak Chopra, it's free. I got this information a few years back from my meditation teacher, and am in no way affiliated with his organisation. It's a good tool to get into the habit of meditating.
Like Tickled, I sometimes panick when I'm going out for a short walk (500 meters), halfway, I start freaking out I won't make it back home...
Before, I would freak out on the bus or the metro, that someone would step on and start shooting people (I live in a safe city), most of the time I was calculating and preparing what to do, how to hide or run if such thing happened.
I've been living like this for years, knowing I wasn't crazy, but that it was after all a crazy thing to think about...
Or I get sudden attacks of claustrophobia.
Automatically starting breathing excercices to avert an anxiety attack may be helpful. There is plenty of information on the internet, easy breathing excercices.
MarieLS