AutoCAD Civil 3D :: Cannot See Parts Of Drawing After Changing Views

I am having an issue with a drawing I have been workign on in Civil 3D. In the drawing I have a corridor and many section views thereof. I was performing some section edits and had been working with two model space viewports so I could keep track of the alignment while performing the edits. When I exitd the section editor, one of my two viewports remained aligned to the section of my corridor, though the view had returned to basic model space. When I switched back to a single viewport, I was left with the one oriented to a section view as opposed to my plan viewport. I reoriented the view to TOP only to find that that most of the drawing, at least visually, is missing. A small portion of my corridor is visible, but appears to have been mostly eaten by some digital goblin.

Similarly, only parts of the overlay I had behind the corridor are visible. I can x-ref the drawing into another drawing and everything is visible. I can copy and paste anything I can manage to select in my drawing into another drawing, where it is also fully visible. I have a couple of profile views who are missing entirely, save their axis and band contents, which I can still see. If i rotate the view one way or another, the amount of visible information changes, but I can't get everything back.