Bottom screen glitching when I change the brightness?

On the bottom screen of my 3ds looks like a bit of the left side of the screen is being shown on the right side instead, and it flickers between doing that and being normal. If I change the brightness it usually stops glitching, but it still shows some of the left side of the screen on the right. Also it just started showing vertical black lines that flicker on the bottom screen if I have the screen on a low brightness, but this only happens occasionally. I bought the 3ds pre owned so I have no idea if it was dropped or water damaged before I got it but in the month I've had it I have not dropped it or spilled water on it.

Any information on what might be wrong with it would be appreciated :3