Board Thread:Support Requests - Getting Technical/@comment-45183-20150921210429/@comment-168424-20150921221545

Sometimes you can use the back button on your browser to get back to edit mode with the state of the page in the editor before you hit publish/submit. However, I believe this is much less likely in the Visual Editor, this is one of the many reasons I use the Source Editor as my default.

So in short, you're probably screwed. You might want to send a message to Special:Contact/feedback and ask if Wikia is doing anything to help recover from this scenario. If they give any kind of useful answer (or maybe even a useless one), please post it here.