I also bit the bullet and force restarted after letting my laptop sit with a black screen overnight. I could still hear some process working, but after reading on this forum that someone had some luck with restarting I went ahead and did it. I did a regular restart without resetting anything through extra key commands. I got a progress bar with an apple after restarting, then another progress bar and apple. Then another progress bar and apple. I force shutdown again, then used the opt + cmd + p + r keys during startup. That did the trick.