The phrase comes from a Youtube video by cindycandy100 2 years ago called "Donkey Kong Song: I'm Nobody's Hero" from the the Donkey Kong Country episode "Kong For A Day" It involves a short part of DK singing the exact phrase "I don't know whats happening to me" and a plane comes in and crashes with an explosion. Soon Youtube users copied the video and started using phrases such as "I DON'T KNOW WHAT'S HAPPENING TO X" and "OH MY GOD WATCH OUT!!!!!!!!" as a video title.