Everything suddenly shrank and shifted on every single page of a 16 page document!

I had everything aligned and fit on the pages that were finished. I saved and exited out of the file for about an hour and when I reopened it, everything was tiny and shifted on EVERY. SINGLE. PAGE.
HELP!!!
How do I fix this without having to go through each and every page again and making sure all the image sizes and font sizes are what they were before I closed out of the document?! Kind of freaking out.
