1. Yes, when my web host had a problem with the server my VPS was on, and ended up restoring an older backup – which forced me to use my more recent backup, and of course leave them. That was years ago.
2. Make sure you didn’t have a security breach, check your logs and check with your host.
3. Restore last night’s backup… or, if for some reason you don’t maintain backups, ask your host to restore their backup, which shouldn’t be more than a day or two old.
Good Luck