Can't play game because of blurry screen and black borders

[Kale]

So, earlier today, my game was working perfectly fine. It was in fullscreen and stretched to 1680x1050 without any problems, and the visuals were completely clear.

Then I had to go out due to real life issues, and when I came back and turned the game on, boom. Black borders on the top and bottom of my screen, and everything is extremely blurry.

I then went and spent the next two+ hours looking on the internet and trying every solve I could find, but absolutely nothing worked. I've changed my PC's resolution to 1280x720, changed multiple things in the settings file, tried mixing and matching the two, and still nothing has worked.

I was really, really enjoying playing this game until now and am pretty upset about this random glitch, and any potential fixes would be much appreciated.