Half my screen is white

Hard to answer without knowing your model computer. The screen shot shows an ordinary display. Try using a background picture or a theme to see if that shows the same fade. Right click on the desktop and choose Personalize to pick a theme or a background picture.

Run a screen diagnostic - hold the D key through powerup.  Does the same fault show on the test screens?

@SpongeCake 

Nothing wrong with the display.

That's what that Windows 10 wallpaper looks like. If you don't like it, choose another one.