Try acidic foods like oranges, and pickles (something with vinegar) if you can tolerate them -- they're supposed to help get rid of the metallic taste. Also I've heard that brushing your tongue with baking soda or salt can help (though that sounds worse to me right now).
It's supposed to go away after a bit though, at least. Not that that's any real comfort, I know.
Sorry you're dealing with it.