Backup, restore to factory, and restore from backup
If you can import your media to Photos or iTunes in a computer and copy important documents to a cloud server it will give you some resilience in case the restore from backup fails.
(1) How to back up your iPhone, iPad, and iPod touch - Apple Support
(2) Restore your iPhone, iPad, or iPod to factory settings - Apple Support
(3) Restore your iPhone, iPad, or iPod touch from a backup - Apple Support
That will clear any bogus `Other.
If after that the other is still larger than about 6GB then you have apps that generate junk.