Sometimes it is hard to think rationally or even to apply common sense when your emotions are torn apart. That is why the Psalmist asks God to send forth His truth. You need to remember to seek truth in your time of despair. Even if it is a situation that cannot be understood, seek the truth about God's unchanging character. Seek the truth about God to overcome the darkness of despair.
When in the desolation of despair, remember the truth that set you free from sin.
When in the desolation of despair, remember the truth about who set you free in the first place.
When in the desolation of despair, remember the promise from the One who is shortly to come again.
When in the desolation of despair, remember the future that awaits us.
When in the desolation of despair, meditate and own these truths inside your very soul.
For if ye turn again unto the LORD, your brethren and your children shall find compassion before them that lead them captive, so that they shall come again into this land: for the LORD your God is gracious and merciful, and will not turn away His face from you, if ye return unto him. 2 Chronicles 30:9
For his anger endureth but a moment; in his favour is life: weeping may endure for a night, but joy cometh in the morning. Psalm 30:5
I cried to thee, O LORD; and unto the LORD I made supplication. What profit is there in my blood, when I go down to the pit? Shall the dust praise thee? shall it declare thy truth? Hear, O LORD, and have mercy upon me: LORD, be thou my helper. Thou hast turned for me my mourning into dancing: thou hast put off my sackcloth, and girded me with gladness; to the end that my glory may sing praise to thee, and not be silent. O LORD my God, I will give thanks unto thee for ever.
Psalm 3:8-12
He hath not dealt with us after our sins; nor rewarded us according to our iniquities. For as the heaven is high above the earth, so great is his mercy toward them that fear him. As far as the east is from the west, so far hath he removed our transgressions from us.
Psalm 103:10-12
He healeth the broken in heart, and bindeth up their wounds.
Psalm 147:3
He giveth power to the faint; and to them that have no might he increaseth strength. Even the youths shall faint and be weary, and the young men shall utterly fall: but they that wait upon the LORD shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint. Isaiah 40:29-31
Come unto me, all ye that labor and are heavy laden, and I will give you rest. Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. For my yoke is easy, and my burden is light. Matthew 11:28-30
We are troubled on every side, yet not distressed; we are perplexed, but not in despair; persecuted, but not forsaken; cast down, but not destroyed; 2 Corinthians 4:8-9
For our light affliction, which is but for a moment, worketh for us a far more exceeding and eternal weight of glory; While we look not at the things which are seen, but at the things which are not seen: for the things which are seen are temporal; but the things which are not seen are eternal. 2 Corinthians 4:17-18
And let us not be weary in well doing: for in due season we shall reap, if we faint not. Galatians 6:9
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things. Phillipians 4:8
Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil;
Hebrews 6:19
Let your conversation be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee. So that we may boldly say, The Lord is my helper, and I will not fear what man shall do unto me. Hebrews 13:5-6
There will be times when you will most certainly walk through the desolation of despair. But there is no need to be stuck in the misery of that valley. Let times of despair lead to an affirmation of your faith, a time of great spiritual growth.