What is your OS? Did you search for lrcat files on your drive?
If you really did delete your catalog, restore the latest backup catalog.
Mac. How do I restore the latest catalog?
I would suggest you to first try to find your catalog under the recently opened catalog list by navigating to File> Open Recent.
If that does not help pleas restore a backup catalog.
Restore a backup catalog
- Choose File > Open Catalog.
- Navigate to the location of your backed up catalog file.
- Select the backed up .lrcat file and click Open.
- (Optional) Copy the backed up catalog to the location of the original catalog to replace it.