Me too. The same problem. I was trying to send a video to a friend on WhatsApp when there was little disk space left. And on the last moment it gone to recovery and reboot.
ADB SHELL gives error, so I have not door inside my phone.
C:\Users\MyPC>adb devices
List of devices attached
1c92lsghl54ece sideload
C:\Users\NMyPC>adb shell
error: closed