I'm still not entirely sure what happened, but I think I got things fixed now.
The site didn't go down; everything was still accessible, but I could make edits to existing pages, and sometimes had issues getting into the admin page. I rolled everything back to April 30th, and that sort of fixed it, but I still ran into sporadic issues. Then last night, I think a plugin caused me to lose access to the admin page entirely. I tried editing the main folders and files (changed the plugins folder to "plugins.hold" to deactivate all plugins), but as I reactivated plugins the issues would re-occur. So I tried another rollback to April 30th again and went to bed around 2:30am. When I woke up, I didn't get the customary email letting me know that the restore had occurred, and when I tried to access the page, I got a PHP error message on a white screen.
Today I ended up deleting the entire WordPress install, reinstalling WordPress, and then doing a restore from April 30th again. I honestly can't remember if I did any posts over the last two weeks, but if I did, they're gone now. While I was fixing things up, I also cleaned up some weird background issues. There were margins around the content box on the default template that had the background image at a different size, and that caused it to have an odd, blurred border.
This all happened alongside building a new computer. I've transferred everything from my laptop over and now I'm completely migrated to the desktop PC. It's noticeably more powerful, which is nice. AMD Ryzen 5 3600 on an ASRock x570 Taichi (which I picked because it has three m.2 slots and can take a Thunderbolt 3 controller card). 32GB of 3200 RAM, Two 2TB NVME SSDs, another 2TB SATA SSD and a 4TB NAS drive for storage. For graphics, I went with a 2070 Super card. To test out its gaming capabilities, I've been playing Gears: Tactics, and absolutely loving this game. It's an XCOM knockoff, but entirely linear. XCOM is almost certainly more playable, but this game does do some stuff better.
Now I'm way behind schedule on doing ten posts for the month, so I will need to do one every two days for the remainder of the month. That shouldn't be too bad, but I'll definitely have to focus on doing it. I've added a recurring task to my calendar to make sure it's in my face.
I should probably add something here.