Draw a picture that is like a spiral.
It starts with a bright colourful outer ring, slowly changing shades as it moves closer to the center.
Shades that are darker and tints of the original colors.
Keep tinting them till it reaches the center which is as dark as it can get, the blackest black, so much so that it looks like a never ending abyss.
A hole so deep that looks like you'll never get out of it.
A hole so dark that no Ray of light can reach.
A hole so dark that nothing is visible, not even your own thoughts.
A hole so deep that how much ever you try, you'll just keep going down.
A hole so deep, I've got dirt under my nails that I can't even see, and still no sign of an opening.
It's that Sinking feeling...