Odd Screen Glitching?

Hello,
For the past few months my hp laptop has had screen issues. One day I was using it nomally, and the whole screen went black and glitched out. When it came back on, there was a box in the corner of the screen that looked like an odd glitch. At one point I poked the screen with my finger, and the box expanded, and it continues to expand if the laptop gets touched or moved, although it is not a touch screen laptop. Now it almost takes up the whole screen.
Has anyone else had this issue or know how to fix it?