Apparently Lost My Old Catalog

This post is essentially an offshoot of another post I created recently asking how to deal with the fact that I'm almost entirely out of space on my laptop running Lightroom (and other Adobe products). It seems like someothing went horribly wrong even before I got the chance to unload all of images to an external drive -- almost all of my images (and presets) are missing! Maybe it's just coincidence, but I clicked on my Lighroom Classic icon as usual, and some kind of box popped up about saving the catelog and how it would not be compatible with older versions of Lightroom, something like that (in retrospect, I seriously wish I screenshoted this). But the bottom line is that when Lightroom loaded, it was like it was brand new installation! It gave me little introductory tour as if I was using it for the first time, etc. It's like the max-out status of my machine caused some mechanism in Lightroom to seriously fail.

The good news for me, if you want to call it that, is that ALL of these files ARE still on my machine. In fact, I'm still maxed out on space (so right now I'm still maxed out on space AND I can't access any of these images in Lightroom, so kind of the worst of both worlds). So it's like the 2024 folder is still there, but that entire folder is missing from my Catelog.

No matter what, it's not like the images are totally gone because, again, they're still on my hard drive. And many of them were never worked on in the first place, but some of them were, and I would hate to lose all of those edits. The question is therefore, is there any way to restore Lightroom to its status before this happened so that I can THEN finally complete the process of moving them to an external drive while still preserving them?