Hey @agentnightingale,
Firstly, the best solution for your website right now is to restore a working backup. If you are not aware of this, please try contacting your web host if they could restore your site from a date when your site was still working.
Regarding downgrading, we provide one previous version called the Stability Release. You can download it in your Accounts Page. Click on Single Licenses > Specific License > Stability Release
Regarding the issue, we have no reports that the Global Blocks were removed after an update. We need first to know if this issue is really caused by our theme and not by 3rd party factors such as customizations.
With that said, please perform all the troubleshooting procedures listed in our Common Issues article here: https://theme.co/docs/common-issues
You can get back to us if this issue is not caused by custom code, 3rd party plugin, or other 3rd party factors.
If what you’ve provided is also a live site, it’s strongly recommended that you copy your live site to a staging site in order to not disrupt your live site’s operation. This is also to avoid the risk of breaking your site while troubleshooting.
Thanks.