This is a temptation from the devil, pure and simple. Go to confession and tell the priest all your doubts and worries, the sins you are afraid you committed, and how you are being tempted to despair. It’s hard to tell if you are having trouble sleeping because of the despairing thoughts, or if they are coming because of the lack of sleep. Either way, you need a good night’s rest. Say some night time prayers, such as the Night Office in the Divine Office and prayers to your guardian angel.
During the day, meditate on these:
From the saints:
St. Benedict taught that “One should never despair of God’s mercy.”
St. Bernard of Clairvoux wrote, “God is not the Father of judgement, but only the God of mercy; punishment comes from ourselves.”
"How happy I am to see myself imperfect and be in need of God’s mercy. "
–St Therese of the Child Jesus
“In what can I hope, then, or in whom ought I trust, save only in the great mercy of God and the hope of heavenly grace?” Thomas Kempis
From the Diary of Saint Faustina:
“The greater the sinner, the greater right he has to My mercy.”
“I am sending you with My mercy to the people of the whole world. I do not want to punish aching mankind, but I desire to heal it, pressing it to My merciful heart.” (Diary 1588)
“My heart overflows with great mercy for souls and especially for poor sinners. If only they could understand that I am the best of Fathers to them and that it is for them that the Blood and Water flowed from My heart as a fount overflowing with mercy.” (Diary, p. 367)
“Eternal God, in whom mercy is endless and the treasury of compassion — inexhaustible, look kindly upon us and increase Your mercy in us, that in difficult moments we might not despair nor become despondent, but with great confidence submit ourselves to Your holy will, which is Love and Mercy itself.”
**Scripture:
**
“Be merciful, even as your Father is merciful.” (Luke 6:36)
“For thus says the high and lofty One,
the One who dwells forever, whose name is holy:
I dwell in a high and holy place,
but also with the contrite and lowly of spirit,
To revive the spirit of the lowly,
to revive the heart of the crushed.” (Isaiah 57:15)
"You that fear the Lord, wait for his mercy,
do not stray lest you fall.
You that fear the Lord, trust in him,
and your reward will not be lost.
You that fear the LORD, hope for good things,
for lasting joy and mercy.
Consider the generations long past and see:
has anyone trusted in the Lord and been disappointed?
Has anyone persevered in his fear and been forsaken?
has anyone called upon him and been ignored?
For the Lord is compassionate and merciful;
forgives sins and saves in time of trouble.
(Sirach 2:8-11)
“But in your great mercy you did not put an end to them or abandon them, for you are a gracious and merciful God.”
Nehemiah 9:30-32
“For I desire mercy, not sacrifice, and acknowledgment of God rather than burnt offerings.”
Hosea 6:5-7
“Who is a God like you, who pardons sin and forgives the transgression of the remnant of his inheritance? You do not stay angry forever but delight to show mercy.”(Micah 7:17-19)
“Once you were not a people, but now you are the people of God; once you had not received mercy, but now you have received mercy.” (1Peter 2:9-11)
“But for that very reason I was shown mercy so that in me, the worst of sinners, Christ Jesus might display his immense patience as an example for those who would believe in him and receive eternal life.” 1Timothy 1: 15-17)