Hello,

I did not change or delete anything. You can find the categories you have created in the Dashboard > Products > Categories: https://gyazo.com/a8dd13aa173b7b31309d8aa39ef60ec0

You can export the content and then import it back into the site. You can do that by means of Dashboard > Tool > Export /Import. In any case, make the full backup of your site.

Best Regards