M8 Wont enter recovery/is bootlooping

[FEA5T]

I have an M8 stuck in a bootloop.

I am able to access the Bootloader menu but not recovery.

Fastboot, Reboot, Factory reset and Recovery options all cause the phone to reboot into the bootloader menu.

USB Debugging was disabled and I cant boot Android OS.
Phone is stock ATT locked.
Plugging into computer and running RUU fails with Error [170].

Any thoughts on how to fix it?