Check the chatbox on loading your game. I think it specifies a command.

Off the top of my head, I think /kill ?

Hi,

You could activate the console and use the "pos" and then "goto" commands, or you could use a mod to shift-click on the map for an instant teleport home.

https://www.pcgamer.com/valheim-cheats-console-commands/

or

https://www.nexusmods.com/valheim/mods/251

if you have access to console commands you can fly yourself out.
or from what i found you can use /killmyself or /respawn in chat without the need for cheat commands.
the last part was found via google search. so not sure how accurate it is.

It's /die in the chat to kill yourself

Can you create a fire? If so, there's the run into the fire trick! I've done that a few times. You can also take a few deep breaths of the smoke. That takes a little longer, but it's also effective.

If your food has run out, or if you're not in a big hurry and want to wait until it drops off, you can probably also run up the walls and jump a few times to die from minor fall damage. If your skill is not high enough, you may not be able to get enough height to do damage, but, do it enough, and you'll eventually get enough still to complete the task... which will then knock it back down, since you died.