The worst feeling in the world

It's only been about a couple of minutes, but it feels like hours. Your lungs are screaming, but your brain isn't listening. It's gone dull. Forgotten what it's supposed to do. It's registering nothing but the dull throb of dirty, black blood trudging through it like sludge. There are dark spots in the corners of your vision. You're panicking, but you don't know why and you don't know what to do about it.

Then suddenly, it's over. Out of the blue, you remember how to breathe. It's a beautiful sensation. It's like the stroke of dawn, when the sun's first ray breaks over the horizon, slowly painting everything it touches. It seeps colour into a monochrome world. Everything changes, shadows disappear. The memory of great, big gulps of air returns to your lungs. And you follow that memory, mimicking it.

Except you're underwater and it's dark.

That feeling you just felt? It's nothing. Nothing.
Compared to the worst feeling in the world.