Thanks for the quick response, Ralf!
I tried the duplicate/clone mode last night, and that screenshot is the error I got when trying to launch Skyrim. Also note that the resolution is set to 1440×900, maybe that is because my main monitor that I am duplicating is 2560×1440? Maybe I should try switching my main to my left side 1080p one and disabling the rest for now.
Thanks for the advice, I hope you get yours soon!