Here’s what worked for me.
unplugged all TB and other accessories.
reset smc.
neither of those two had an effect on their own.
turned off Mac. Held right shift key when powering back on. Startup disk app loaded.
unlocked mac hard drive with password from that app. Clicked restart button from that app.
Mac rebooted and didn’t kernel panic and after two password prompts I was back in business.
hope this helps someone