I once deleated almost all of the photos on the SD card to my camera! They were pics of our first and only (so far cruise!) Thanks to Kim Komando I was able to retrieve them!
Kim Komando has a web site with daily tips and is full of computer tech related information.
Do not download anything else onto your computer!!! until you have exhausted any and all attempts to retrieve your 'lost' work.
Like others have said - it's still there somewhere.
Good luck.