You could try using file recovery software and and scanning the default AutoSave directory. They files normally deleted if Excel shuts down properly. The time it would take to scan, it might be easier and faster to re-do it. Puriform Recuva is good a good recovery software (free). For the best chances of file recovery, don't use your hard drive until you recover the file, put whatever file recovery software you use on a USB stick, and recover the file to a flash drive.
Save early, save often...