Select and mask

… How do I get the full image back with the new layer mask? …

By @torstend73391893

Sorry, but I don't understand what exactly you want.
You want to see the full image without the layer mask? Then [Shift]+[click] on the layer thumbnail of the layer mask in the Layers Panel.

Unfortunately I don't know which new mask you mean. In your screenshot I can only see the current layer mask of your layer "Lag 0 copy", which hides parts of your image and furthermore the layer mask of your colour correction.

Check the Properties for the Hue/Saturation panel.  It looks like you have the Lightness slider moved all the way to the left making the layer beneath it black.  Center that slider to fix it.

You could try looking at the history panel to see if the history states go back that far.  If there isn't any history before the crop, it may not be possible.