device: Nexus 5, hammerhead.

Yesterday my phone was fine, today it's stuck in a boot-loop. I didn't do anything, I've never rooted or flashed it. I tried clearing cache and using factory reset:

When I boot into recovery mode, it says:

E:Can't open /dev/block/platform/msm_sdcc.1/by-name/misc (No such file or directory)
E:failed to mount /cache (No such file or directory)

If I click factory reset it says:

== Wiping data...
Formatting /data...
E:format_volume: failed to open /dev/block/platform/msm_sdcc.1/by-name/metadata
Data wipe failed.
(about 10 more errors about /cache subdirectories failing to mount)

1 . Is it a bad disk?

2 . ADB seems to fail but I'm not sure if it's a driver or USB Debug set to false issue.

C:\>adb devices
List of devices attached
039bb160215d2f7b        sideload


C:\>adb reboot bootloader
error: closed

C:\>fastboot reboot
< waiting for any device >

(It hangs forever here)