System become unbootable

Disk has been encrypted during install process (ZFS Auto). However,
system become unbootable after adding a new user key with "geli setkey
..." command and appropriate values to /boot/loader.conf file. There
something like:
geli_da0p2_keyfile0_load="YES"
geli_da0p2_keyfile0_type="da0p2:geli_keyfile0"
geli_da0p2_keyfile0_name="/boot/da0p2.key"

Encrypted partition da0p2 can be attached with geli when I boot from USB
stick. Have no idea what to do next as I have no experience with ZFS.

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