I am with Scott on this, similar experience and strategies to handle my anxiety. Also, I've learned that to a significant extent my anxiety tends to be conditional and triggered by bad habits (surprise, yet another bad habit!). Due to a basic level of worry and fears, sometimes I am not dealing with things (often practical tasks) that I should and that can add a pretty intense extra dose of it. I am often surprised how calm I can become if I regularly stick with plans, do not procrastinate, complete things on time etc. Another good one is not allowing myself to get overly obsessed with and stuck in things because that can also get in the way of doing important things and increase my worries.
As for the panic attacks, I used to have them with varying frequency, before I started to drink heavily and of course during. Somehow I think for me awareness really helps, knowing that what I am experiencing is anxiety. I don't recall having a full blown panic attack since I've started to acknowledge the symptoms for what they are, at first it was conscious control (grounding exercises etc) but somehow it has become automatic and if I experience intense symptoms, they don't tend to last long are are less bothersome.