What you have does indeed sound more like production and development. General practice it that between these two the data only goes from production to development, but never the other way.
Having true staging, you can push the data from to production, is challenging precisely for the reasons you describe. There are solutions around, but even those on commercial and pricey side don’t quite promise reliable two-way synchronization with live environment.
The low hanging fruit for you would be to find and eliminate those ways in which your content authors can break the site. Their roles and permissions should be locked down and there should be procedure for content going live, rather than authors just pushing publish.