Over a third of the psalms can be categorized as Lament Psalms. They are important for us to read and to think about. They give us words to express our own sorrows, and they give us permission to use such words, to admit such feelings.
The usual format includes: addressing God directly, voicing the complaint, and, often, expressing trust in God to handle the problem.
Psalm 13 begins, "How long, O Lord?" Are we uncomfortable voicing complaints and doubts?
The psalm asks the Lord to pay attention to the problem--because the situation is so dire that the psalmist must have help. What has it taken in our lives for us to realize that we need God's help? Or, are we usually more aware of God when we are in trouble than when things are going well? Or, the other way around?
Following the usual pattern of a lament, Psalm 13 closes with an expression of gratitude to the Lord for rescue from the dire situation. Then, the psalmist turns to the congregation, "I will sing to the Lord, because he has dealt bountifully with me." When we are grateful to God, do we remember to mention that to others?
Suggested reading: James E. Bowley, Introduction to Hebrew Bible.