Disappearing Text/Can't Save As New Name[ADDRESSED]

Sweet, so I was attempting to copy text from a section I haven’t worked on in two days. I highlighted all 800 something words and admittedly hit the wrong keys, the ones for “undo.” POOF went everything within that file. I tried undo, redo, paste and everything however the only thing that appeared was what I previously copied. I tried reloading the project seeing as I did not save but it is gone for good. This is kind of devastating seeing as I’m doing NaNoWriMo and that was half a day’s work…
Since that happened earlier today I decided that I would periodically save copies however when I go to “save as…” and try to save my project under another name Scrivener freezes. I cannot back up my work.
Not. Cool.

have you tried 'back up to" it saves in a totally differnt location…