Display Scale Issue on Late 2013 iMac with Mojave

Howdy,

I am running a Late 2013 iMac 27-inch with Mojave 10.14.6.

My entire screen is zoomed in to a degree that makes it almost impossible to do anything. I have tried changing display settings from "Scaled" to "Default for Display," but there is no change. Also, when I close out of system preferences and reopen it, my change does not seem to get saved – it reverts back to "Scaled." There are no options for "Scaled" resolution either, just an empty selection box where the different scales would normally be seen (see below).

I thought I could resolve this by updating to Mac OS Catalina, but when I tried that, I learned the installer window is too big (goes off the screen at the bottom) so that I am unable to push the "continue" button, which is somewhere offscreen.

• Is there another way of changing the display scale that I'm not finding on forums?
• Is there a way to resize the installer window so I can access the "continue" button and finish installing Catalina?
• Would installing Catalina even fix this problem in the first place?

Thanks in advance to anyone who is able to help me with any of these questions.

Thanks,

Flynn

P.S. I have tried multiple system reboots as well as multiple NVRAM and PRAM reboots, to no avail. Swearing doesn't seem to help either.

[Re-Titled by Moderator]