Hi Michael,
We are not able to understand what exactly happens to your website if design cloud importing is the reason
Does the design cloud importing is the reason behind your issue. If that is the case, there is no automatic way to undo installing a template within the theme, so if you cannot get a backup restored via your host, the best thing to do is to manually delete any images added to the WordPress Media Library and removing the installed template from the Template Manager. However, this isn’t a perfect solution, so you should definitely approach your host first.
Most hosting providers make backups available, so I would suggest contacting them, if you haven’t already, as that would be the quickest and easiest way to undo the effects that installing the Design Cloud content had.
Please keep in mind that restoring the older backups may cause a loss of the content you updated in-between times.
Thanks