Can't see photos after upgrade to 5s

Hi all, I just updated my phone from a 4 to a 5s. The problem I'm having is that when I open camera I can see there's 842 of 842 photos in the camera but unfortunately I can't see any of the images - they're all greyed. There's a little cirlcle spinning and it says loading but nothing appears to happen. Scared I've lost them! I tried looking at them through instagram and same thing. HELP please