Photos storage?

So it looks like your storage problem is not about a Photos Library. You can use the same Finder search to look for images of any kind, put them in order of size, and see if your problem lies there. You can also search around for folders that are very large.

You know, I never look at that. It does seem to include more than your Hard Drive. But if it meant only Photos Libraries, which category would all the other pictures be in?

And there's this: when I look at that display on my own system, it says for Photos, 45.7 GB. When I add up the storage from my several Photos Libraries, it comes to 206 GB. In addition to that, I have another 350,000 other images on my hard drive. So I have no good idea of what those numbers in that display mean. I suppose someone does.

If I want to clear out some room on my hard drive, in Finder I put the folders in order of size and look inside the big ones (because making a change in a smaller one makes a smaller change.)

One of the things that takes up a crazy amount of space, by the way, is video. Look into that...

Try using the Finder search to hunt for a ".photoslibrary" or other picture files. The "Choose Library" dialog does only a limited search.