It's almost like your brain say's "don't forget to Panic".

Frustrating isn't it? Really this can get almost worse than having them. You can spend alot of your time focusing on them when they are not even happening. Truly a vicious cycle. Just try to remember (especially when you are having one) that it will go away. It is impossible to live in a state of Panic. Our bodies are not capable of that.
I try to use a visual method when I am having one. I Imagine that it is a tidal wave coming for me, Instead of running from it, I walk into it. Just let hit you and breathe as regularly as you can. Sometimes I even count.
Waiting for them, and dwelling on them after they come is actually much worse.
Sometimes I also try to think of them as just physical pain, and get macho about it and think that I have taken much more pain than this, and I can take even more.