Something unusual is happening in this verse. The psalmist is not praying. He is talking to himself.
Why are you downcast, O my soul? It is a question, and questions are what you ask something you do not automatically believe. He has noticed the discouragement and instead of simply agreeing with it, he asks it to explain itself.
Most of us do the opposite. A feeling arrives announcing that things are hopeless and we treat it as a news report rather than an opinion. We never ask it for evidence.
He does not pretend the feeling is absent either. It is right there in the verse, named honestly and left standing. He is not performing cheerfulness. He is refusing to let a mood have the final say.
Then he gives his soul something to do: put your hope in God. Not in a better week, or a resolution, or an explanation. In a Person who has not changed since the last time this happened.
You are allowed to question your own discouragement. It is not always telling you the truth.
