Lines across the bottom of screen

Theres a problem which started yestersay where there were lines at the bottom of on Macbook's screen. It forms like bottom of the screen of when it start. (If you don't understand you can look at the image) It also fades a little when I don't use it. (Like in the image) The mouse is still slightly visible when its moved toward the glitched area. The lines also flicker very slightly.

I think the cause of this was the Macbook overheated and brunt some display cable in the device. I have been using it for very, very long. It was also making air rushing noises.

If you could see whats going on and suggest a way to fix it I would be very grateful. Thanks!