K5 Fastboot problems

A few days ago, my I turned on my Kindle Touch's wifi, and it updated itself. When I came back, it was stuck at the loading screen with the person reading under a tree.

I've tried charging it and doing a hard reset, but it didn't seem to have any effect. Next I followed the guide here: http://www.mobileread.com/forums/sho...d.php?t=170929 but I get stuck with fastboot waiting for the device. Any advice would is appreciated, as I would love to get back to reading.

tl;dr: fastboot is stuck on <waiting for device>

Thanks in advance for any advice.