How to clear library without deleting reviewed movies

Sony bravia updated to 6 andoid. 0 changes except now my external usb drive mounts like new every time i pull it out. So kodi doesn’t recognize same files in same folders and need to update information, which leads to duplicates. I know i can delete all non existing files(duplicates), but can I delete only files that i didn’t watch? I just want to keep my progress for different TV series.