I,ve lost four thousand pictures

Hi there, I,ve just lost nearly four thousand pictures... I thought I had duplication in my computer as I saw Pictures/My pictures and Pictures/My pictures, so I deleted the first one, and I couldn't stop it, the computer deleted all within 4 seconds. I tried to find them in the Trash, but there was only older stuff, about 300 pictures. I kept searching... and when I emptied the Trash, could...