1. did you actually send them to the unit, or were they all edits in the queue?
2. like all computer files, you should have a backup and a backup of the backup, and a 3rd party cloud backup for when your 3 copies fail.
3. to get back the factory presets, you can flash the firmware
4. have you tried unplugging the unit from the usb and then turning the unit on? it is probably too late for that because it seems like you already sync'd. but in the future, that will probably help.