Computer Crashes/Freezes During Game Play/Youtube Help Please!


May 12, 2015
Hi! I'm just an average guy with a modernish laptop, bought it 3 years ago. A problem has sparked up and I have no idea what to do. Help please!
Recently, about a week ago, when I was playing Hearthstone(you might know the game), the game started to have little black shapes on it. It's hard to explain, but the game crashed and I reopened it. Starting then, every time I'd open up the game, ONLY when tabbed to the game my display would start to flicker and waver and eventually it'd crash the game. I tried a lot of things and nothing worked. Eventually, even going on youtube created this problem.
Herein lies the bigger problem. After trying to fix it for a while, it didn't just start to close my programs. The whole computer would freeze, in the weirdest way. First, the screen would freeze at what I was doing, then it'd bring me to a blue screen with white lines and emit a REALLY loud buzzing sound. I closed my computer and tried a few more times to fix it, and then it just stopped letting me log on to Windows.
I got a friend to fix it and I'm able to log on again, but Youtube occasionally makes the display freeze(The error message just says display stopped working but was able to fix itself) and logging onto the game makes the screen to flicker and waver, the way it was just before a crash. I closed the program before it fully crashed, but it's a bit annoying to have a laptop that can't play games at all. Can anyone tell me what I should try to do to make it work again?

Sorry for the essay, but I would really appreciate help!

My specs :
Operating System: Windows 8.1 64-bit
Processor: Intel(R) Core i7-3632QM CPU 2.20 GHZ
Memory: 8 GB RAM
DirectX Version: DirectX 11
GPU: AMD Radeon HD 7500/7600M series

TL;DR : My computer crashes when I play games. When it crashes, it makes a really loud screeching sound and doesn't stop until I manually turn it off w/ the power button. Help please?