AdamR: One of the little things today was a stomach ache. I had a small stomach ache today, probably because of stress, and I started thinking I have internal bleeding. (In my defense, that actually happened two months ago and I almost died.)
So I get that thought stuck in my head, then I get light headed, my heart rate goes up, and I become paralyzed with fear.
I return to normal after 10-20 minutes, but the thought keeps occurring throughout the day, even though I know it is irrational.
As for your methods - I like tough love.
Oh man, I sympathise. Sorry to hear you went through something life threatening, good to see you made it and are still around here. :-)
I assume that the odds are pretty low for the problem to occur again, right?
Now, you have two things going for you - one, you are aware that it's rather unlikely to be something that serious again, that's a big thing to hold on to, and two, the attack triggered by the thought doesn't last long. Have you tried to do things that are pleasant or stress-relieving when the thought starts creeping up to you? What do you enjoy doing the most?
Ah, and thanks for approving my methods. Perhaps we could find something suitable for you, though that helmet you're wearing presents a bit of a challenge. ;-)