You're not a waste of anything.

[... Yeah, that's a familiar one.]

The things that were important in your own world are still there, waiting for you. Being here just means that you're helping a different cause for now. You can do that just by being yourself, without even having to try. Eventually the gods will send you back and you can return to what you were doing before.

[-- Oh. While they're on the subject--]

Dying doesn't mean the same thing here as it would there.