The term "feeling down" is a literal description of the physical position that goes with feeling sad or discouraged . People who feel that way sit or stand curled over, head drooping, eyes downcast.
If you will physically shift your position to upright, shoulders up and straight, head up, and eyes focused on something in the upper third of the wall in front of you, you'll notice a change in how you feel. You will also be shifting into a visual mode rather than a kinesthetic (feeling) mode of information processing.
So, when feeling down, look, stand, sit up. See what happens when you do.
