It happen to me in the past where I lost a wall of text since I didn't click preview and then I accidentally close the page or reload. But, after that, whenever I want to create a long post, I edit on notepad first, then I copy the text and post in this forum.
This incident is mostly experienced by members that uses phone gadget for posting, on clicking the preview you'll have to scroll to see how your wall of texts looks like and if you ain't careful through you could just reload the page leading to a loss of the entire wall of texts. It's an experience I had faced many times while using a phone but don't remember having it happened to me using my laptop because you get to have everything appearing on the screen.
It's painful and tiring having to rewrite same texts over again which I am recommending you use laptop if you own one. I don't subscribe to the idea from some members about having to write their post elsewhere (notepad), copy it to paste it on the typing space for posting. Using a laptop you don't need those procedures.