When I switched to orthographic view with Numpad 5, the view in my 3D view doesn't look to be properly orthographic at all. Is there any way to fix this?
The view is orthographic. I think what you're seeing is an optical illusion. The angles you have described as 'low' and 'high' are in fact the same, as shown below where I have rotated the the image and inserted horizontal parallel lines:
The lines marked in red are also of equal length and parallel.