I cried unto God with my voice, even unto God with my voice; and He gave ear unto me. In the day of my trouble I sought the Lord. My hand was stretched out in the night without ceasing. … – Psalm 77:1,2

Turn to the seventy-seventh Psalm, and you have a battlefield there. Should you ever have to fight the same battle, by looking through this Psalm, you will see David’s shields and spears, and you will soon learn how to screen yourself with the one, and how to do exploits with the other. Here is David fighting with despondency-an old enemy of mine. I daresay some of you are afflicted with it. But observe how he fought with it. The first weapon he drew out of the scabbard was the weapon of all-prayer. And how grandly he used it! “I cried unto God with my voice, even unto God with my voice.” Satan trembles when he hears the sound of prayer. They are the conquering legions that know how to pray. Despondency soon flies when a man knows how to ply this all-conquering and ever-useful weapon of petition to the Most High.

Then note how he used this weapon continually. “My hand was stretched out all night,” saith he. If the first prayer did not help him, he prayed again; if an hour’s prayer did not bring him peace, he would pray two hours; and all night long he kept at it. You will get a like result too, my brother, if you exercise a like perseverance-you must get a like result if you know how to linger at the mercy-seat. When he had used the weapon of prayer, what did he do next? He took out another spear. It was that of remembering God. He had long enough pored in thought over himself and his present sinfulness and weakness, and now he remembered God’s mercy, God’s faithfulness, God’s lovingkindness, God’s power, God’s covenant, God in the person of Christ. Oh! this is indeed to prepare a salvo against the enemy, and to fortify one’s own position with fresh succours. He can win the battle that knows how to use this artillery of remembering God. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0972.cfm