All games are way too big on my screen unless ran at 1366 x 768p.

Idk what is causing this. I have a 1080p monitor, but if I run games at 1920 x 1080p the game is stretched way too far, like I can see maybe 70% of the game the rest is cut off.It's weird.PC specs;i3 2120
R 9 290
8gb RAM

It probably has something to do with the graphics driver. Try changing GPU scaling settings and see if it works for you.