We are all told to always think positively, but it is healthier to face and experience shadow emotions, come face to face with ourselves honestly, perhaps not label what we feel, but experience all of the spectrum of experience with equanimity.
Art that also mirrors sadness, anger or fear can open up those parts of us who are viewing it and can give us a space to release those emotions.
This piece is done with pen and colour pencil. 
the drawing interprets sadness very well.