I've never really used it...
https://www.klennet.com/zfs-recovery/
Do you feel that's something you need still?
Or do you mean try reinstalling truenas
Well thats disappointing but im glad you found the wedding photos... There is some recovery software you can buy but at this point you are probably ok.
read some forums try this:
sysctl vfs.zfs.max_missing_tvds=1
sysctl vfs.zfs.spa.load_verify_metadata=0
sysctl vfs.zfs.spa.load_verify_data=0
then try the import thing we did earlier above