We are truly sorry to hear about the pain you're experiencing, but we must address this situation through the lens of scripture and sound biblical principles. Firstly, it's important to understand that God has a purpose and plan for your life, and that includes the relationships you have. It's clear that you care deeply for this person, but it's also crucial to align your desires with God's will.
We must also address that you did not mention the name of Jesus Christ, Jesus, or Christ or an abbreviation such as IJN (In Jesus Name). It is important that prayers are made in His name. It is only by the name of Jesus that we have access to God. Also, there is no other name by which we can be saved. But what things were gain to me, these I have counted loss for Christ. (Philippians 3:7 WEB)
In every situation, we should seek God's face and ask, "Lord, what would you have me do?" Rather than focusing on getting her back, focus on becoming the man God has called you to be. It's encouraging that you're willing to address your faults. Remember, God is more interested in your character than your comfort. He wants you to grow in Christlikeness. You must surrender your desires to His will.
Trust in Yahweh with all your heart, and don't lean on your own understanding. In all your ways acknowledge him, and he will make your paths straight. (Proverbs 3:5-6 WEB)
Regarding the relationship, it's important to note that God's design for relationships is that they should be moving toward marriage. If this relationship was not built on a godly foundation with marriage in mind, it may not be God's will for you to pursue it. God does not condone sexual immorality, so if there was any sexual sin involved, it's important to repent and turn away from that.
But because of sexual immorality, let each man have his own wife, and let each woman have her own husband. (1 Corinthians 7:2 WEB)
Flee sexual immorality! "Every sin that a man does is outside the body," but he who commits sexual immorality sins against his own body. (1 Corinthians 6:18 WEB)
Now, let's pray together:
Dear Heavenly Father,
We come before You in the name of Jesus, lifting up our brother in his time of need. Lord, we ask that You comfort his heart and help him to trust in Your will for his life. Help him to surrender his desires to You and to seek Your face for guidance. Help him to grow in Christlikeness and to become the man You've called him to be. If it is Your will, Lord, we ask that You restore this relationship, but ultimately, we want Your will to be done. In the name of Jesus, we pray. Amen.
Be strong and courageous. Do not be afraid or terrified because of them, for Yahweh your God goes with you; he will never leave you nor forsake you." (Deuteronomy 31:6 WEB)