Hmm. I think you can use console commands to teleport back to certain coordinates.

If you're trying to avoid that, I'd say you're in need of rescue. If there is a way to find your current coordinates and you could post them here. I'd be willing to join to attempt a rescue. I'm not too privy to any console commands, but if you're interested I'd be willing to explore the possibility.

Originally posted by wizard_of_woz:

Swim as far as you can and then log out. When you log back in you will have full stamina.

Oops. I completely forgot that was possible. That may be your easiest answer OP. Hopefully you have some decent food on you for your stamina.