Separate artboards into single AI files?

Have a magazine type spread I'm working on for client. I made an a file with about 18 artboards. Everything was working great until it wasn't. Illstrator is being way too slow only on that file. I'd like to separate threm all into their own files so I can work in peace. I tried using the libraries but it saves everything as "artwork" and I'm no longer able to edit my assets unless I save single asset one by one and sometimes that doesn't work. I tried clicking "Save" and no "illustrator options" pannel shows up. "Save as" greys out "Save as different artboards". Any advice? Project is due by tomorrow at latest.