You have your Zotero data directory stored in cloud storage folder, which you should never do, since it's very likely to corrupt your database.
You should close Zotero and immediately move it out of there, and then try restoring from a backup (likely either one of the zotero.sqlite.* files in your data directory or, if you have version history for the cloud storage files, an earlier version of the main database — you should check database integrity from the Advanced → Files and Folders pane of the Zotero preferences to see if a given database is corrupted).
Upgrade Storage
You should close Zotero and immediately move it out of there, and then try restoring from a backup (likely either one of the zotero.sqlite.* files in your data directory or, if you have version history for the cloud storage files, an earlier version of the main database — you should check database integrity from the Advanced → Files and Folders pane of the Zotero preferences to see if a given database is corrupted).