"but I will meditate upon Your kindness to this lovely land"
-States that you must try to look past bad thoughts and note the good things in life, this will probably bring back the 'happy' you.

• "In bitterness of soul Hannah wept much and prayed to the Lord."
  You must want to be happy, when you are depressed, it is easy to stay in this state, you must want happiness in order to obtain it.

-Finding God as a method to battling depression is the ability to see happiness and the potential for Good, even when the day seems bleak, and hanging on to these thoughts until it consumes your soul.