Aperture frozen-can't quit to shut down-no idea what to do

My Aperture 3.4.4 is trying to import something (I actually don't know what it's importing) and has been for the last 3 days, resulting in a non-functional Aperture program that is driving me crazy! I have a photo shoot tomorrow (Thanksgiving) that I really need it to start working again. I know everyone says don't "Force Quit" but I can't close Aperture any other way, and the force quit isn't even working. I tried to Shut Down, but the Aperture needed to be quitted, and it can't. What is another way I can quit Aperture, or make it stop running so slow/stop importing? (I'm tried to cancel the import, but it just says cancelling). Thank you so much.