Crashing (1.8 and 1,9)

So I started up a 1.8 world I created a while ago, and when I opened it up the screen flashed and I saw the clouds and the horizon and then my game crashed. I tried opening it up a few more times, but I gave up and made a 1.9 world instead. This world was good for about5minutes when that world crashed as well. I repeated the process over and over until I knew it was a problem with Minecraft itself.