PC Comes Back ... With NO DATA

Good Morning ,

So today, my computer came back with absolutely nothing in it and I've lost all of my hard work of downloaded fandom videos.
I've had stuff in it since 2005.  . .and now there's nothing LOL

I'll have to sit and look through stuff to find them
Why doesn't Johnny's have a youtube ;w; 

WHAT DO I DO !?  (。┰ω┰。)

This is so sad