ouch!
Ctrl Shift Z, should redo (I suppose you already know that)
You could try checking your temp folder for recent auto-saves, (in another instance of blender don’t close the original yet in case someone has another idea)
Hi, if the keyboard short cut to redo not working try the Edit>Redo several times to get back to where you stopped.
This is a classic example why you should save as incremental every 15 or 20 minutes of work .
That’s weird, Blender used to behave this way years ago, but this hasn’t been a problem in a long time. You are using the most recent Blender version, right?
I don’t know if this would work in a case like this, but you can always try finding your computer’s “temp” folder, Blender leaves auto-saves and whole scenes just as they were when you last quit (can be useful to retrieve a scene after a crash).