My file was not saved even after I saved it many times, what now?

I have been working on a large Illustrator file, it contains several artboards (it's a booklet). I constantly save the file as I'm working on it, and even though it's slow, it says it saved the file. I decided to save as a PDF so I could send it to the person I'm making this so he can give me some feedback. So BEFORE I saved as a PDF, I made sure to save my AI file once again, and THEN I saved as PDF. I sent the PDF file to the person so he can review, then opened my AI file again to continue working. I almost fell from my chair when it opened, because it didn't save any of the changes I've been making for several hours. I will literally have to recreated all the pages I worked on this afternoon. I didn't save the PDF with editing capabilities because I don't want anyone to make changes to my file, so I can't even use that PDF 😞 Any way to recover my work? I literally spend well over 6 hours on this today. Thanks.