I've accidentally set too much TNT explosions and destroyed my hard worked on builds, what do I do to reverse the damage quicker?

Restore a backup

If you have made a backup you can restore it and rebuild the progress made. No backup? That's a problem, but not impossible to fix. You can use commands like /fill and /set block to make the rebuilding process way faster.

Let's suppose you don't know how to make a backup. Well it's pretty simple, just go into your worlds and copy/duplicate the world, and then name it something like "world backup date" you should frequently backup worlds, especially ones you work on often