I open minecraft, and I click on Multiplayers or Singleplayer. I load a world and it either gets stuck and stops responding at "Loading terrain" (Multiplayers) or "0%" (Singleplayers) Why? Is it my laptop or is it Minecraft?

You see what I expected was to play Minecraft regularly, but then, I open Minecraft up, and what do I see on the top? "Minecraft 1.11.2 (Not responding)" This has been going on for I don't know, three days? Why is this happening to me? I love Minecraft!