If this is an ongoing issue for you, please see your doctor for treatment. In the meantime, one thing you can try is light therapy....go outside in the sun for awhile, if there's no sun, visit a tanning bed, it will have the same effect, both will aid your depression.
Whenever I'm depressed I just turn on my favorite tunes or watch one of my favorite movies. Studio ghibli movies are the best. Also anime. Or anything that will make you laugh.
Sometimes depression is a chemical imbalance. Notice the foods you have been eating. Eating healthy unprocessed foods will show you if this depression is a reaction to your food intake (and pills, smokes, etc.).
Exercise to get your body moving, then emotions may flow through more easily and you won't feel so stuck in the depression.
Take your focus off of yourself and find value in helping someone less fortunate - that will help you feel good about yourself.
Live in appreciation!
Maybe try doing things to make you happy, listen to happy music, take walk, whatever is making you unhappy eliminate it from your life