After a single APT command gone wrong made my Debian installation unusable, I decided to reinstall Linux. I tried to back up everything to my external hard drive, but it kept unmounting, so I elected to use Filen (a FOSS cloud storage provider) instead.
It was only after installing openSUSE Tumbleweed with KDE Plasma that I realised I hadn’t actually synchronised the folder I had moved my backup to; meaning I have lost everything but a single Minecraft world (which I had backed up to a Compact Flash card in February).
Tl;dr: Double check your backups, and use physical storage whenever possible.
If you have any friends or family in a nearby town, ask if you can leave an external hard drive at their house. You could make a full disk encrypted backup of your machine every week or so and then when you visit them leave a copy of your backups. It may give you more peace of mind if the data is valuable like journals or family photos.