I need Help!

Hi, I was trying to boost my FPS and I have maybe clicked on something I wasn't suppose to on my computer options and when I log on to play a match it gives me a half of a screen.

I don't know how to describe it but the bottom section of the screen is in the middle of my screen so I can't see the top of my screen or in other words, the scores.

So everything was shifted up and I know everyone can't play with half of a screen, especially the bottom half only showing!

Any help would be greatly appreciated, thanks..