Welcome to the club. Has happened to many of us.
Fill in the form at https://rekordbox.com/en/support/contact/
Pioneer will get in touch and ask you to send zip files of one of your directories along with requesting other info.
Would recommend you don’t open Rekordbox again until they tell you too, as may make the issue worse by overwriting your back up files.
I suspect the issues not reversible and you’ll have to go back to your last back up but guess Pioneer will let us know once they have reviewed the files.
Fill