TLDR: Web host had massive hard drive failure. Everything was lost. Now, several months later, they managed to recover the files, and I’ve managed to reinstate them. There might be some weirdness here and there that I haven’t discovered yet, and if there is, I will be fixing that in the coming week.
The full Story: My web host had a catastrophic RAID failure, and had no off-site backups. Apparently, that’s my job. They must have have done something wrong however, because after they tried to fleece their customers for a forensic hard drive recovery service and didn’t get enough takers, the eventually decided to pay for it themselves and only charge their users $20 a site to retrieve what they could. Fortunately, everything appears to have been recovered for this domain.