I will pray for you, since most Christians have "hidden" sins that they struggle with, whether they want to admit them or not. Your willingness to bring this request here publicly is a huge step toward change. I applaud your courage.
I have always loved using Psalm 19 as a source of strength against my habitual sins, especially verse 13. I included the definition of "presumptuous" at the end of the passage, since it is used in the NASB, and I find it quite fitting. It also helped me remember the verse. I have included the whole chapter here, but I highlighted some verses that seem to fit your situation (related to your nightmares), but also have stood out most in my own prayers.
PSALM 19
1 The heavens are telling of the glory of God;
And their expanse is declaring the work of His hands.
2 Day to day pours forth speech,
And night to night reveals knowledge.
3 There is no speech, nor are there words;
Their voice is not heard.
4 Their line has gone out through all the earth,
And their utterances to the end of the world.
In them He has placed a tent for the sun,
5 Which is as a bridegroom coming out of his chamber;
It rejoices as a strong man to run his course.
6 Its rising is from one end of the heavens,
And its circuit to the other end of them;
And there is nothing hidden from its heat.
7 The law of the Lord is perfect, restoring the soul;
The testimony of the Lord is sure, making wise the simple.
8 The precepts of the Lord are right, rejoicing the heart;
The commandment of the Lord is pure, enlightening the eyes.
9 The fear of the Lord is clean, enduring forever;
The judgments of the Lord are true; they are righteous altogether.
10 They are more desirable than gold, yes, than much fine gold;
Sweeter also than honey and the drippings of the honeycomb.
11 Moreover, by them Your servant is warned;
In keeping them there is great reward.
12 Who can discern his errors? Acquit me of hidden faults.
13 Also keep back Your servant from presumptuous sins;
Let them not rule over me;
Then I will be [e]blameless,
And I shall be acquitted of great transgression.
14 Let the words of my mouth and the meditation of my heart
Be acceptable in Your sight,
O Lord, my rock and my Redeemer.
presumptuous: (of a person or their behavior) failing to observe the limits of what is permitted or appropriate.
