Revert tags
                    I have made some wide-reaching changes to my tags involving thousands of items that I regret and would like to revert. Doing so manually is not an option. I have complete backups of everything. What do I need to replace in order to regain the tag situation I had earlier? This is Zotero 6.0.30 running on MacOS 12.7.2.                
                             Upgrade Storage
 Upgrade Storage
Zotero automated backups have saved me. Also my Mac TimeMachine backups have allowed me to select the earlier version of a file I want. That said, you will need to, one way or another, need to carefully assess the amount of effort needed to fix the tag problem while retaining complete library records. I urge you to take some time to consider what is the best solution.
If it is useful knowing what I would do, I would manually work with the tags. You are still on Zotero 6. Zutillo may streamline your tag work. Someone else will need to comment as I haven't tried to use Zutillo to manage/edit tags.