Sprottenham
I remember we had that kind of problem in the old Forum years ago, so I got into the habit of making everything clear in a Word document and co-pasted it in when I was satisfied with the content.
I'm certainly not saying it's okay, but at least you haven't lost two hours of work.
NB: Have you tried reloading your login? I was involuntarily logged out this morning while writing a message. When I logged back in, the unfinished message was nowhere to be found. When I wanted to write a new message, my unfinished message appeared.