You should be able to get rid of lxddsk by adding a new file /var/snap/lxd/common/lxd/database/patch.global.sql
With the content
delete from storage_pools where name='lxddsk';
Then the next time LXD starts, it will apply the patch and clean up the orphaned storage pool and things should start working again.
Here’s a link to the documentation for this feature:
https://documentation.ubuntu.com/lxd/en/latest/debugging/#running-custom-queries-at-lxd-daemon-startup