Yikes!!  If this JUST happened I would say QUICK -- contact your Canvas Admin -- you may need to put in a ticket to Canvas Support to help you and *maybe* revive it for you.    Or if your Canvas Admin has access to a Test Instance or Beta Instance, they could check there to see the info.  It's possible they can see the info if not too much time has passed and take screen shots or download info for you, at a minimum.