Work gone after saving

I spent four hours editing on this software the clip was less than 5 minutes long, I saved and left my computer till the next day, then when I opened it to continue editing it, everything was gone. All of my hardwork earsed. The prodject was still there but with none of my music, files or anything but the title of the clip at the top. I have the most updated version of the software, and im upset that everythings gone.