Pages is Hiding All of My Text

I was editing a document that I had previously copy & pasted from a Word document. All I remember was trying to hit back space in order align a certain text, but it didn't, so I pressed several more times & that's when it happened. All of my work seemed to get erased. I clicked undo, which made it reappear, I kept typing, but had to hit backspace again. When I did that, everything erased again. I hot undo one more time. This time, just by typing all my text erased. I hightailed the text and apparently, it's still there just hidden. Now every time I open ANY Pages document or template, all of the text is hidden. What happened & how can I fix this?