Lost save on world 670+ days

I'm sorry to hear of this, but unfortunately there is no way to restore the save unless you has automatic cloud save backup enabled on your PSN account. In that case you might be able to restore it, though I'm not sure the exact procedure. After your report I've been testing the rollback function but have yet to reproduce the issue.

I future you should consider periodically backing up your savedata, either to PSN cloud or to a USB stick, to safeguard it against accidents.

Probably hit "regenerate world" instead of rollback by accident lol