Everything is deleted help

Everything is deleted, i followed a long tutorial in a series of videos, now everything is gone. because he said in the video to use Control+W, Apprently unreal switched it to Control+D.

Is there a way to recover old files??

ControlW just means close now. So I think you just closed something, possibly the content browser?

Yea you are right. I found out it later, geez were i afraid at first.