New to Scrivener. Lost some text

Hi, I’m new to Scrivener. I highlighted half of my text to do a word count, and it disappeared. Please help!

Hi

Click in that document / editor
Edit / Undo
Ctrl-Z

Do that until it comes back. Whatever you do, don’t quit the app or close your project.

Ok, Thank you! I’ll try this.

I accidentally put scene four in the trash and I couldn’t retrieve it. When I tried, I stupidly selected a back up file that was six months old, and so now I’ve lost 12 more scenes! What can I do to get back to my current screen?