I was changing the fonts and accidentally selected all the content of the note which got overwritten. Command + Z doesn't seem to work and I have no backup. Is there a way to recover? I have tried the solutions in Overwritten Mac note but it doesn't seem to work.
Even if you’re sure you don’t use iCloud, go ahead and turn it on and check https://iCloud.com for notes and deleted notes.
Even if you’re sure you don’t use time machine, connect a drive and see if you can enter time machine to browse local backups and snapshots.
These two methods have saved me and also saved people that were convinced they didn’t have backups.
I hope you have a backup of some sort to piece together the notes database and don’t lose this work.