You're not alone, I have anxiety attacks all the time.
I usually try to keep my cool in public, but inside I feel overwhelmed and scared.
I can feel my inside world cracking and my muscles becoming cold and stiff. I want to escape when I have them, just to run away as far as I can. But I know in reality I won't let myself, sometimes I can't. Its all just a bad dream, I wish it was, but I know better than that. The darkness that comes over me is like a pyschological tsunami, I have trouble breathing as I feel my lungs tightening up. I can see the world moving past me as if nothing were happening. They can't see the turmoil within, why should they?
That's pretty much the best way I can describe my own attacks. Anxiety attacks occur over the MBTI board, more likely so with 'IXF' and 'INT' types.
There are medications out there available for people with anxiety problems, if its becoming a daily or weekly occurrence then you definitely want to go see your doctor about it.
How I generally deal with anxiety is by listening to music, in public I carry my MP3 player and noise cancellation earbuds. I stop focusing on myself and the people around me and focus on the music, its a good distraction. Everyone has something that works for them, but music is my suggestion.