Hi Sky,
You can't keep running Joomla 3.10. You need to update to Joomla 4, and then to Joomla 5. This is not easy, but is the only way to keep using Joomla and not get your site hacked again. Then you need to apply the JoomShaper critical security updates which are detailed in this new blog post here:
https://www.joomshaper.com/blog/security-update-for-joomla-3-users
The blog post applies to Joomla 3, 4, 5, and 6.
The way to properly do this is to take your site offline, then restore it from an uninfected backup copy. Set up the restored site at a staging URL that's not accessible to the public. Then begin the steps to migrate from Joomla 3 to Joomla 4. Once you are on Joomla 4, you can begin the JoomShaper Page Builder and Helix plugin updates. Then you can update to Joomla 5. Eventually you can make the Joomla 5 site live.
Again, this is a complicated sequence, but it really must be done. Joomla 3 is vulnerable to being hacked.