Attempting to recover from soft brick

I have been trying to recover from a soft brick that suddenly happened on my phone, I think I can fix it as I can get into fastboot..

However I am trying to flash system and I am getting a write failure.

I am using this guide: https://docs.google.com/document/d/1...2XP6wjJE4/edit

and the latest stock android (the newer 5.1.1.)

I was having problems before in steps before that but I actually found that doing a fastboot oem lock / unlock and then trying actually let me get farther then I was able to before (before it failed on the bootloader-hammerhead part)