Assuming every country has an embassy of each country (i.e. mine was 12 hours of flight time away)

How will you travel to the embassy?

Hitch-hiking for example. It's not forbidden to ask people for help, most will refuse but there's often some kind soul that will give a hand.

If I have no other better option: walk.

If you happen to be in a city where an embassy or consulate of your country actually exists, typically embassies are in the capital city of a country, and if you come from some countries there may be consulates in some other "main" city, but that's it.

You may need to "walk" hundreds of km to reach one of those.