Piling on:
I've used Gemini 2 to deal with duplicates in Finder Folders, but I would never let it or any such app touch my Photos Library! The Photos Library controls all the images through its Database, and messing with files inside the Photos Library without properly informing the database, as you've found, really screws things up! The Library may become permanently corrupted.
Apparently you have been poking around inside the Photos Library package, and that risks screwing things up even worse! Any changes, even inadvertent ones, will confuse the database and make more things inaccessible. If you insist on messing around in there, do it only with a separate COPY of the Library! The original picture files are in the Library, but they have been given new unique identifiers different from the original filenames. The original filenames are (or were) linked to the original picture files through the database. If you can't link those files back to the database, then all edits, comments, crops, and other additions and alterations will be lost. There may be smaller Preview files inside the Library that show the edits, but they will be lower resolution for fast loading.
I'm guessing that you are not using iCloud Photos-- that might have saved you. Sending a backup copy of the Library to a separate external drive would have saved you, also.
You can try re-building the Library by closing Photos and re-launching with an option-command-click on the Photos app icon. It could take a long time to rebuild. It might work. It might not.
Good Luck, and let us know how it goes…
