1. don't panic
2. take a deep breath
3. do what jommy said:
Remember to backup the (corrupted) wallet just in case.
Then place one of your backups in said directory and rename it wallet.dat
backups will take some 100 transactions before going out of sync, so you're probably good with your latest backup.
Anyway don't panic, if you have your backups, you're 99% fine.
Thank YOU jommy and mtrycz. It might be working. It appears to be automatically syncing in classic mode. Thank YOU more than mere words can express.
The moment you said you had backups I knew you were golden. It's not like you had an ssd failure or something xD