No collections have been deleted in your library in the last year. A bunch of items were deleted last August, and a few collections were deleted last June.
But it looks like you haven't actually been syncing Zotero for months. If you were only working locally without syncing, and then you accidentally deleted your Zotero database, you would've had an empty Zotero library, and syncing would've just pulled down the couple remaining items in your online library from last year.
People usually do this by accident when they're trying to clear disk space:
Upgrade Storage
But it looks like you haven't actually been syncing Zotero for months. If you were only working locally without syncing, and then you accidentally deleted your Zotero database, you would've had an empty Zotero library, and syncing would've just pulled down the couple remaining items in your online library from last year.
People usually do this by accident when they're trying to clear disk space:
https://www.zotero.org/support/zotero_data#locating_missing_zotero_data