Mouse Movement & Resolution Issue

I'm not sure how to fix either of these issues I'm having unfortunately.
Mouse movement seems to rotate only one way and gets locked if I look up or down.
The resolution is very pixelated and buggy on 1080p and not sure what settings I should use to fix this.
Sorry if these are noob questions, but any help would be awesome! First time playing a private server, so forgive me if I'm doing all this wrong.

 

Is the game resolution set to 1080p in height or the windows settings, since it's pixelated it's most probably related to the game resolution which is downscaled. To upscale the resolution go to Settings->DisplaySettings->Game Window->ScreenResolutionSettings change the dropdown value