There's nothing like the sudden crash of discouragement that follows a period of solid, positive action. You've been doing all the right things, making great progress, and then suddenly find yourself in a blue funk, utterly depressed by the seeming futility of your actions. It's an emotional sinkhole.
I find that increasing my understanding often gives me a feeling of control over situations that otherwise leave me feeling helpless. I'm going to start by defining the word, "discouragement":
dis·cour·age·ment
noun \-mənt\
: the act of making something less likely to happen or of making people less likely to do something
: a feeling of having lost hope or confidence
: something (such as a failure or difficulty) that discourages someone
The derivation is fascinating. It literally means "to lose heart." Kind of an ironic thing to be writing about on Valentines Day.
This is ridiculous, of course. You can't lose your heart. You still have it. It's still there.
We forget sometimes just how alive we are. Setbacks, failures, reality adjustments -- these remind us that we are not superhumans. They are a kick to the ego-crotch. Of course we feel less alive and less vital. Of course we "lose heart."
The solution to discouragement, as near as I can tell, is to increase a personal feeling of vitality. Learn something new. Listen to exciting music. Get out and do something physical. Hell, just washing the dishes, accomplishing something as mundane as that can make you feel that much more vital.
The important thing is to remain active. To keep pushing, keep moving, keep on keeping on. And just like popping the clutch* on a car with a dead battery, you'll be fired up and racing off in no time.
*I realize this metaphor will be lost on most people. You know what? Google it sometime when you're feeling discouraged. Learn something new!