Cannot Flash Stock Firmware - Bricked for Good?

Alright, I'm at my wit's end here. I started today to install NetHunter on my Nexus 7 2013 WiFi. I ended today trying to figure out why the heck I can't even flash the stock image anymore. Here's my situation:
I can no longer boot into Android on my Nexus 7. I can access the bootloader and recovery mode. I've tried using the Nexus Root Toolkit to flash Android 6.0.1 to my device, and that fails every time with the following, even if I choose to flash it on normal or soft bricked/bootloop mode. A log of what happens is at the bottom of this post.
This I discovered apparently corrupts the system and userdata of the device. I then install TWRP and get the error telling me it cannot mount system, data, usersystem, etc. After messing around, wiping various file systems, I can get everything to mount. I then go back to the bootloader and try to flash stock, and the process repeats.
So obviously this wasn't working. I tried wiping everything in the stock android recovery, and I still get the same errors. When I try to mount /system in the default android recovery I get the error "E:failed to mount /system (Invalid argument". So I have no clue what to do at this point. What can I do? Is the file system just totally corrupt? It was working fine this morning when I set out on this whole adventure. Hopefully someone can help me. If there's anymore information that I can provide I gladly will, just tell me what I'm missing. Thanks in advance.

Also, forgot to mention I have tried various USB 2.0 and 3.0 ports and 4 differnt USB cables, two of which I know are of good quality.

Log:
Flash Stock + Unroot [WugFresh Development]
------------------------------------------------------------------

< waiting for device >
sending 'bootloader' (3911 KB)...
OKAY [ 0.131s]
writing 'bootloader'...
OKAY [ 1.206s]
finished. total time: 1.340s
< waiting for device >
rebooting into bootloader...
FAILED (command write failed (Unknown error))
finished. total time: 2.024s

sending 'boot' (7444 KB)...
OKAY [ 0.241s]
writing 'boot'...
OKAY [ 0.334s]
finished. total time: 0.578s

erasing 'cache'...
OKAY [ 0.113s]
sending 'cache' (4664 KB)...
FAILED (command write failed (Invalid argument))
finished. total time: 0.119s

sending 'recovery' (8190 KB)...
FAILED (command write failed (No such device or address))
finished. total time: 0.004s

erasing 'system'...
OKAY [ 0.565s]
sending 'system' (843393 KB)...
FAILED (data transfer failure (Unknown error))
finished. total time: 2.285s

Creating filesystem with parameters:
Size: 13346254848
Block size: 4096
Blocks per group: 32768
Inodes per group: 8160
Inode size: 256
Journal blocks: 32768
Label:
Blocks: 3258363
Block groups: 100
Reserved block group size: 799
Created filesystem with 11/816000 inodes and 91981/3258363 blocks
erasing 'userdata'...
FAILED (command write failed (No such device or address))
finished. total time: 0.006s

Creating filesystem with parameters:
Size: 587202560
Block size: 4096
Blocks per group: 32768
Inodes per group: 7168
Inode size: 256
Journal blocks: 2240
Label:
Blocks: 143360
Block groups: 5
Reserved block group size: 39
Created filesystem with 11/35840 inodes and 4616/143360 blocks
erasing 'cache'...
OKAY [ 0.351s]
sending 'cache' (10984 KB)...
FAILED (data transfer failure (Unknown error))
finished. total time: 0.696s

rebooting...

finished. total time: 0.006s