The Cloud stole my photos from my iMac

I only use a desktop and I have thousands of photos. Just last July I transferred everything to a brand new iMac which I purchased when the video card died on the old one. I eventually had it repaired as a backup, but transferred everything to the new unit.

I don't trust the Cloud and never used it to back up my photos at all, but my iMac has 2TB of memory and I have plenty of space left on it. My Photos program has all of my raw files, which are taking up the most space.

I had many folders of photos that were downsized, Photoshopped, and watermarked for posting on Facebook (and in the past, message boards.) Recently I went into one of the folders and most of the files were missing -- at random (I tend to title them simply -- b1.jpg, b2.jpg, and so on.) I managed to locate some of them on the iCloud drive and the rest in an iCloud archive. How and why they were there is a completely bizarre mystery, but I was relieved to find them and restore them to my computer.

Last night I went looking for more that I wanted to post. Well, they aren't on my hard drive anymore (not my doing), so I checked iCloud and found the folder for that particular subject. There were only SIXTEEN random photos out of the 500+ files that I originally had in the folder -- and no archive for them! I still have the raw files, but I had spent countless, COUNTLESS hours editing all of these for posting over the years. And they didn't take up much space compared to my Photos files. I just don't get it.

I even checked my old iMac -- all of my transferred files (largely condensed Desktop stuff) -- are still in one folder on it. I didn't delete them. But again, the photos that disappeared in the Cloud are gone. 😠

I've done Google searches on how to recover these files (supposedly it can be done), but I can't help but wonder if all of the instructions are outdated. I went into iCloud and I'm not even seeing the options that they're telling me to choose in order to get my photos back.

Needless to say, I'm beyond frustrated, and it doesn't look like many people are answering questions on this forum these days. Help!