Restore Page After “Editing Every Page Glitch”

I know it’s not a glitch, and I’m still not entirely sure why it happens, but I have the same issue that all the pages get edited when I make a single edit on one page… I realize there are many posts about this on the forum, and that I can attend to this by adding a content block. Anyways, I lost an entire 2-3 days of work because after completing a page, I switched to the next page…. and as you can guess all the info on my first page was lost. How do I restore it? It would save me a big pain in the neck. Thanks

The page I need help with: [log in to see the link]