Lament gets pretty messy, gutsy, and honest to the nitty grittiest core of the seat of our emotions.
Yet, as raw and sometimes egocentric as it might appear, it is still prayer and part of the process of rearranging our thinking.
If you cannot pour out your most tumultuous cries to God, who knows you completely, what will you do with them? You have to pass through them and exhaust them to the point of moaning and fainting to the place where there is no prayer left for you to voice and no energy to deliver it --- sometimes.
Then, you let His prayers in and through you carry you to a new place, eventually, the high ground of love and praise. In the meantime, do not be afraid to let God see you at your worst. He already does and loves you anyway.
Psalms like this show us the dark side of ourselves so that we can be reassured that no darkness is stronger than God's light.
When I remember God, I moan;
when I meditate, my spirit faints.- Psalm 77:3, ESV