This wasn't really an accident. CS6 was a great suite, but it was made years before Mojave. It was unwise of you to keep upgrading your system if you wanted to freeze your apps. Also, if you ever installed CC it took over the licensing of CS6 and you will need to do a deep clean to run CS6 without a CC subscription.
Still, some people get parts of CS6 working ok. I assume you've still got your disks and serial number, and have installed it ok (or not?). But something doesn't work. Please tell us what goesw wrong.