Flashing/Flickering Screen when moved/moving

Alright, so I got this laptop (touchscreen Asus Q504UAK) used from a Best Buy about a week or two ago. Today is 7/6/2017. Yesterday it started acting weird, with the screen flashing and/or flickering. Upon inspection, I noticed the screen was, in fact, still on and there, but it was extremely dark and pretty much unseeable. The laptop registers clicks from the mouse and taps on the screen and it works like it's supposed to despite the screen problem. I have to tilt the screen back and fourth for the brightness to appear to see what I'm doing, and it takes a long time to set it up in a way where I can see. I have to be gentle and slow and depending on its "mood" it will work without flickering when I tilt the screen (very little, that is, it still flickers).

I've read something that it might be a cord or something, or like an LED problem? Even a hard drive thing? This problem keeps happening, but the laptop is completely usable otherwise.

Edit: Could this be a video card issue??

(Not sure if this is important, but the top row of buttons didn't and haven't worked since I've gotten this. You know, f1-f12.)