Is it possible to trap yourself in the Nether?

After entering the Nether is it possible to trap yourself without a way back to the overworld except via death or game commands?

I know it's possible to relight an extinguished Nether portal using flint/steel or even a Ghast's fireball but what can you do if your Nether portal is destroyed?

I was, rather foolishly, moving the only Nether portal I had from one point in my Nether base to another without spare obsidian. Using diamond tools I had dismantled the Nether portal and was in the process of moving it to a more secure room in my fort when I accidentally pressed the "drop" button on my keyboard. Because of my bad luck I had dropped the obsidian over a pool of lava - making it irretrievable - and no longer have enough to construct a new portal.

There was a series of mistakes that led to this happening: not having a backup portal, not bringing spare obsidian, previously demolishing the four corners of the portal such that those pieces of obsidian cannot be used. In spite of my errors, is there any way I can still escape the Nether or will I need to kill my character and have them respawn in the Overworld?

This question is intended for a survival singleplayer but answers can be encompass survival multiplayer too.

4 Answers

According to the Wiki, you can find both Obsidian and Flint and Steel in Nether Fortress chests. Go find a nether fortress and try your luck by collecting chest loot.

I see multiple ways for you, to get back with minimal losses.

1. Like Quijibo mentioned, you might get lucky by finding obsidian in Nether fortresses.
2. Since the nether is unloaded when there is no player in it (in general of course there are ways to have it loaded), you could drop all your items near the original position of your netherportal, jump into the nearest pool of lava, respawn in the overworld and reenter the nether through the overworld, which should generate a new portal and your items would still be there. (Or get a chest from a fortress, in that case you don't risk any despawn)

In Minecraft 1.16, you can find nether gold ore and craft ingots by making a crafting table (you can find wood in warped and crimson forests) then craft gold ingots and barter with piglins until one gives you obsidian.

Why not dig up nether sand - it behaves the same as upper worlds sand or gravel - just drop it in the lava where your obsidian fell - obsidian doesn't get melted by lava so its still there ... dig out the lava after you successfully dried up a big enough area