What is the worst physical pain you've ever been in?

Weirdly, I was mowing grass and the push mower kicked up a pointed rock that imbedded itself in my lower leg, all the way against the tibia bone.

Imagine stubbing your toe with a nuclear warhead.

It bled and all that, but I nearly fainted from the pain - and it lasted for nearly an hour.

The doctor told me such missiles fired from a lawn mower are traveling 250 mph.

Blessedly, eventually it stopped.