Losing written copy after writing it in a template rather than a file

I'm a light user of Adobe Express. I use it mainly to create graphic design layouts for copy that consists of my own poetry. I then post to social media. 

I've developed a layout with a background, font usages and guides. Adding additional pages using that formatting seemed like an unnecessary recreation of the wheel. Certainly Express offered templaes on the page level as well as the file level. Well, yes it does. It's not as stupid and crude as I thought. I created and saved my layout as a template. 

Then I made extensive edits to my copy. 

In the end, what I thought was a file was me writing into the template, adding pages to it. I thought it was like creating an AE template. Once you save it, you're back to work in your work project. Nope. Express doesn't do it like that, it seems. There's no way to know that it doesn't work as other Adobe Apps work. So I assumed. 

And now I've apparently lost two hours of carefully crafted work.

Or have I? I saved something upon quitting, when I chose 'Save and Exit.' What did I save and where might it be? And might Adobe's devs consider this oddball use-case and provide a breakpoint where a user can choose whether to continue working after spinning off a template? 

Cheers

Richard, Adobe product professional user since 1991.