Trouble Uploading In iMovie 2015

Okay, I have a verified YouTube account, so I can post videos over 15 minutes. I recorded my screen using Quicktime Player, edited and added music in iMovie, and pressed the shared button to share it to YouTube. It loaded about halfway, and then it just stopped. At 50% uploaded, it stopped uploading. It still said it was uploading, but it didn't move. It's now three hours later. I've tried exiting out of iMovie and trying again, canceling uploading and trying that again, and many other strategies. However, none of them work. My video is 15 minutes, one second, has audio from music in iTunes that I do not need copyright permission to use, and uses video from Quicktime. I've never had this problem before. I'm positive there is nothing wrong with the video or audio, since I've posted these kinds of videos before. I have a Macbook Pro with OSX. I have checked my app store updates, and everything is updated. Please help me!