I was on Windows and then my MacBook went to sleep. There was no warning, and I just figured it was low batteries. So once I got home I plugged it in, and the screen started flickering. It wouldn't stop, so I stared at the blinking screen to save my work, then went to restart. Once restarted, There was no more crazy flickering but all my icons are in their negative colors, and distorted. Any idea of how to fix this and what had happened?