Soft brick - cannot flash via recovery or Odin

Basically woke up with my phone as a brick... phone crashed when my alarm was supposed to go off (luckily I was already awake) and now hangs on the boot splash screen.

Device is an i747m, previously running S3Rx 3.0 (Android 4.3) with MK5 bootloader and modem. CWM 6.0.4.7 installed.

I am able to boot into both recovery and download mode.

However, in recovery mode, I get the errors:

Code:

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E: Can't mount /cache/recovery/command
E: Can't mount /cache/recovery/log
E: Can't open /cache/recovery/log
E: Can't mount /cache/recovery/last_log
E: Can't open /cache/recovery/last_log
E: Can't mount /cache/recovery/last_install
E: Can't open /cache/recovery/last_install

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Furthermore, if I try to factory reset, I get the error:

Code:

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Formatting /data...
Error mounting /data!

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While in recovery, I am not able to flash a new recovery or ROM. There are no errors when flashing, however, after rebooting nothing has changed. I'm assuming that's because the system cannot access the storage.

Through Odin, I can flash TWRP with no errors. However, once I try to boot into recovery, I am still on CWM 6.0.4.7.
Through Odin, I am unable to flash ROMs (trying to flash 4.3 MK5 stock rom). I am using Odin 3.07 on a W7 x64 computer with Samsung drivers installed and an official Samsung USB cable.
I receive the error:

Code:

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<ID:0/003> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> I747MVLUEMK5_I747MOYCEMK5_I747MVLUEMK5_HOME.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/003> Odin v.3 engine (ID:3)..
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Get PIT for mapping..
<ID:0/003> Firmware update start..
<ID:0/003> sbl2.mbn
<ID:0/003> NAND Write Start!!
<ID:0/003> FAIL!
<OSM> All threads completed. (succeed 0 / failed 1)

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It appears that there is a problem with the internal memory since I can't read/write, but I am unsure if it is fixable.
I have come across this thread, but I am skeptical if it will work since it is for the Verizon S3.
I also came across this thread in my research, but I can't get cygwin to download >.> It seems promising, but I am unable to try it at the moment.

Any help or suggestions would be greatly appreciated. Please let me know if any additional information is required.