Hey guys I need help with my HP Pavilion dv6-3217cl

Since almost a year ago my laptop has been causing me problems:

I belive the first problem was when it got hot the screen suddenly developed white lines crossing it horizontally (I managed to fix this by using the laptop as if it was a tower PC and connecting it to a screen through the HDMI port).

Then I turn it off once and the next day when I tried to turn it back on the screen stayed black but the power, charging, wireless, the hard drive and the HP logo on the back stayed on (the wireless and hard drive turn orange instead of white, like if they were off) and the caps lock light would turn on and off constantly and the fan starts running like crazy (This problem is "fixed" by overheating the laptop, to the point where it turns off and then restarting it. Please help with this because I'm sure this is damaging my computer a lot).

And recently vertical lines of different colors started appearing on my screen, doesn't matters if it is connected to an external source or not. The lines fill up the whole screen and between them the background is a grey color(I haven't actually found a solution to this problem and I'm starting to get desperate).

I know the easiest solution would be to get another computer but right now I don't have the means to do that. If I don't have another option because this one has finally reached the end of its life, I believe it has been already five years with me, I will see what I can do but first I will like to try fixing it so please help me if you can.