Argh sorry to hear about this, it happens at the worst of times and to all of us.
Not sure about mac but check your backup location, in windows it’s the recycle bin.
Check out the backup files in your files location backups have a .3dmBak extension.
When you crash, always work on that crashed file, if you get it to open, in a new version. If the file opens, first thing, do a save as and save a new version before doing anything to it.
I constantly save versions for this this reason, even though I have backup turned on and even then in the heat of battle one can forget to backup or save as until it’s too late.
If you used the Save command during the modelling session, a previous version will be found in the Trash.
Apart from that, Rhino 8 uses the macOS Versioning system that should take care of creating all necessary backups while you work. Clearly, that failed in this case.
-wim