Problem with closing lightroom

Hi! I have a MacBook Air and I can't close out Lightroom. I have tried clicking the red button in the corner to close out of it and I have tried literally EVERYTHING to force quit it and it's still not working. I can't turn my computer off to restart it, because it's saying that I need to close out and I am not able to do so. I also can't update the app. Lightroom is the only app that is not working. I can no longer upload photos either on it either. I have never had this problem before. I need HELP!