Just had the same issue with the same machine and HD . I had just imported some mini DV footage via Firewire using quicktime . Dumped the footage to an external and trashed the file on the Mac. It hung and would only restart in Safe mode.
I think upgrading to an SSD will fix most High Sierra issues as most I am having are with SATA spinners. All my other machines with SSD work great.
Oh the days when APPLE JACK used to fix everything!
Cheers!
FS