This is a Psalm of David. It was written at the time Saul was pursuing David in the wilderness. David’s persecution included the poison of slander that was designed to set people against him for no reason and the laying out of traps and snares meant to trip him up. In David’s case the ultimate goal of his enemies was David’s literal physical destruction. He was indeed in dire straits.
Almost as a follow-up to David’s commitment to defend God’s honor by slaying the wicked (Ps. 139.19-22), he finds himself asking the Lord to rescue him. In this Psalm, we see a threefold structure to his prayer: A request for help/rescue, a request for vengeance on the wicked and David’s confidence in the Lord’s justice.
How important it is for us to understand that today as well as in David’s time, the battle is still the Lord’s. We do not have to take the full weight of life upon our shoulders; God is there to cover our head even as He covered David’s.
I would like to encourage you to approach the Lord for rescue, to let Him deal with the situation and to trust in His justice.