Q: File Vault issues

Initiated File Vault on my MacPro. It immediately became unresponsive and never came back. I tried to star up in Safe Mode, but this took me to a screen with 3 questions (Did you lose your password? Did your keyboard not enter your password? Did you password not work). I had no luck with any of them. If I checked the keyboard question it took me to Apple ID to set a new password, which I did. It then asked me to restart to turn of file vault and proceed. I did so and the machine shut down and never restarted.  The MacPro is 4 years old and worked flawlessly until this all happened.  Anybody with advice?