Hi Lizzie,
Have you made any recent changes to your device? Display and scaling issues are most of the time attributed to the graphics/display hardware of your computer. In the meantime, try to download and install the latest graphics/display driver from your device manufacturer website. In addition, I would suggest the scaling and layout settings by going to Settings > System > Display. Make sure that the scaling and layout and resolution is set to the recommended value.
We're looking forward to your response.