Your honesty in confessing what you have done is not to be taken lightly, and the guilt and shame and exhaustion you describe show that your conscience is not yet seared. You have not hidden your sin in the brighter light of excuse, and that is right, for the lesson from the whole is this, be honest. Sinner, may God make you honest. Do not deceive yourself.
You are right to feel the weight of what you did. To lust after another woman, even in secret, is not a small thing before God, for the Lord sees the heart, and He calls that adultery in the heart. It is sin first against Him, and then against the woman you say you love. To promise faithfulness and then break it wounds trust, and the hurt is deeper when she has been wounded before. That you feel shattered and ashamed is the bitterness that rightly attends a sight of sin, the bitterness for Him as one that is in bitterness for his firstborn, when we see what our sin cost the Christ of God and the wrath it provokes.
Yet there is a blessed truth for you if you will receive it. If by faith you can believe in the sin forgiving God and accept the matchless Atonement which covers all your guilt, then you are even now among the blessed. God Himself has blessed you and neither men nor devils can reverse the benediction. It is God that justifies. Who is he that condemns. It is Christ that died, yes rather that is risen again, who is even at the right hand of God, who also makes intercession for us. At the very same time that the guilt of sin is taken away, the forgiven man undergoes a change of nature. He does not try to make his sins appear less heinous than they are. He confesses all their guilt and heartily humbles himself in the sight of God with a broken and a contrite heart, which God will not despise.
Take care that your repentance is not superficial, for God is not mocked. He sees through the film which seeks to hide the ulcer. True repentance is not only sorrow because you were found out or because your relationship suffers, but a hatred of sin itself and a turning from it and a determination in the strength of God to forsake it. It gives God glory. It says, Lord, I have no claim on You, I have no rights but the right to be punished, and it leaps for joy at the thought that God has set forth Christ to be a propitiation for sin. Repentance is the gift of God. You are not to draw it up from the depths of your own heart as water from a well, but to ask Christ to work it in you by His Holy Spirit through belief of the truth as it is in the Word of God. Look to Jesus. Look to Him bleeding and dying and forsaken, and that sight will beget repentance.
You speak of six months free from pornography, and for that we give thanks, for it is evidence of grace at work. Yet hear this word, can a man find joy in God who still clings to his vice. Will God receive into His favor those who continue to practice what He forbids. To handle a matter wisely is to find good, and the true way to handle a matter wisely is to trust God. That means not being idle, not being rash, but acting in all prudence and uprightness and relying simply and entirely upon Him. Flee every provision for the flesh. Put away every private source of temptation. Seek accountability, bring your struggle into the light with a faithful pastor or mature brother, and walk in the daily means of grace, the Word, prayer, and the fellowship of the church.
You ask for prayer for your relationship to come back even stronger, and for trust to be rebuilt, and you ask not to be judged. We love you enough to tell you the truth plainly and not to mock you with a false comfort. We cannot affirm, celebrate, or ask God to bless a relationship as if it were marriage when it is not. In Scripture, marriage is a lifelong covenant of one man and one woman, and sexual intimacy and living together belong within it. To ask God to bless impurity would be to ask Him to contradict His own goodness. What we will gladly do, and what we will put on our prayer list, is to pray for you and for her as souls before the living God.
We will pray that God, who is not a dead force but a living God with a great warm loving heart, a thinking, active, personal God, will draw you both to Himself. We will pray that He grants you repentance unto life, creates in you a clean heart and renews a right spirit within you, and gives you faith to trust Christ alone and not your feelings or your griefs. Consider who this Christ is whom we bid you trust. He is very God of very God, perfect Man who lived a perfect life. When did He ever lie. He justifies the ungodly and cleanses the wicked from sin through His precious blood. Here is where God and you are at issue. You want to be saved by something in yourself, by being a good guy with morals, but God says He will save you if you trust in Christ. Only trust Him.
We will pray also that bitterness toward God is taken away. You grew up hearing the Word and have rebelled, and now you feel that bitterness. Know that the bitterness of the cross, when rightly seen, makes Christ very sweet. When you find God so kind, so good, so overflowing with compassion, you will smite upon your breast to think you could have rebelled against One who loved you so and sought your good. The goodness of God leads to repentance.
If you truly love this woman, then love her as God commands, with purity, honesty, and self control. Rebuilding trust will require more than words. It will require a complete change of mind about sin, a forsaking of lust in every form, truthfulness without guile, patience, and a willingness to seek counsel about whether God would have you pursue marriage in His time and in His way, or whether for a season you must walk apart to learn holiness. Do not use sinful means to keep affection. Trust your affairs in your Father's hands.
May the Lord grant you not a despairing repentance that leads to hardness, but a repentance that needs not to be repented of, and remission of sins in the name of Jesus Christ. May you trust in the living God who made heaven and earth and who sustains you by His mighty power, and find that to trust Him is to find good.
