I’ve also experienced a similar situation in late January. My system hang due to the vp9 decode issue plus another problem with syncing (my fault) so I forced a reboot in a “not gentle way”. Upon rebooting I found myself with errors on filesystem metadata, the filesystem was not mountable and I was stuck in the initramfs root enviroment.
To everyone that find themself in such a situation I advice caution in order to preserve your data. Given that the tools available in the initramfs enviroment are limited a good advice might be to fire up a distro from a live iso usb/extra partition to diagnose what happened and (if needed) backup your files with the powers and tools of a full distro. I booted from usb, recoved and restored the last snapshot and I was back on track.