Internal Storage corruption?

[Greitato]

Hello. I've been having a problem for a few days now which I have tried to fix, yet was unable to, which is why i'm posting here for potential help in fixing my issue (if it even is solvable).

I run a Samsung Galaxy Note 10.1 (GTN8000) with TWRP 2.8.7.0 and CM 13 (Android 6.0) installed. Warranty already ran out about a year and a half to around two years ago, after which I rooted my device. A few days ago, I was watching a few videos on YouTube with Optimus running in the background (with Balanced Memory Settings activated). Suddenly, my tablet rebooted and was stuck on the CM boot screen for a good half hour before I decided to reboot into TWRP to just restore a backup I made a month prior. As I booted into TWRP and checked the log after starting, I saw:
"E:Mount: Unable to find partition for path '/sdcard'
E:UnMount: Unable to find partition for path '/sdcard'
E:Mount: Unable to find partition for path '/sdcard'
Updating partition details...
E:Unable to stat '/data/media'
...done
Full SELinux support is present.
E:TWFunc::Copy_Log -- Can't open destination log file: '/cache/recovery/log'
EataManager::Output_Version -- Unable to make /cache/recovery
MTP Enabled"
All text that is bold is red on the TWRP log.
Once I tried to restore the backup I made, I saw this:
"Restoring 3 partitions...
"Total restore size is 6575MB.
"Wiping System...
"Formatting System using make_ext4fs function.
Restoring System...
E:extractTarFork() process ended with ERROR=255"
Trying to restore the backup but now with System unchecked, the same E:extractTarFork() Error=255 happened.
Restoring Boot works fine, HOWEVER at the end, I see:
"Updating partition details...
E:Unable to stat 'data/media'
...done"

I tried repairing Data, the log says:
"Repairing Data using e2fsck....
E:/sbin/e2fsck -fp /dev/block/mmcblk0p12 process ended with ERROR=4
E:Unable to repair '/data'
E:Error repairing file system"
When i try to outright delete Data, it says:
"Wiping data without wiping /data/media...
Done.
Updating partition details....
E:Unable to stat '/data/media'"
Trying to wipe the Internal Storage results into this:
"Wiping internal storage -- /data/media....
E:Error opening dir: '/data/media'
Updating partition details....
E:Unable to stat '/data/media'
....done"
^ this leads me to believe that my internal storage is somehow corrupted

I have also tried to reflash TWRP and my device's original firmware using Odin, however this didn't work either, resulting in "Complete(write) operation failed".

Thanks in advance for any help.