Hi there,
Starting off, depression and sadness are two different things. If your low mood is associated with tiredness and a loss of interest in things you used to like, along with sleeplessness, loss of appetite, low self confidence or poor concentration for over 2 weeks, you may be suffering from depressive disorder.
Follow this link to read more about depressive disorder and what you can do to help.
http://wp.me/p8qNXn-7a
Next Steps
Please visit a doctor , if your symptoms persist.
Health Tips
Don't blame yourself for your mood, and don't limit yourself because of your mood.