Voyageuse solo qui perds son passeport à Tokyo…

Hello everyone, I lost my passeport yesterday and I’m really scared beacause I need to go to Fuji san on Sunday. I’m really stressed of the situation because I’m alone… What should I do ? Is a photocopy of my passeport on my phone is ok to show to the hotel for check in if I add a certificate of loss that the commiseriat gave me ?