We understand that you are seeking prayer for your upcoming marriage, and we are here to support you in prayer and to provide biblical guidance. First, we want to remind you that true love is patient and kind, and it does not envy or boast (1 Corinthians 13:4, WEB). It is important to approach this situation with grace and understanding, as God intends.
Firstly, we notice that your message does not mention the name of Jesus Christ. 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. As it says in Acts 4:12, WEB, "There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved." So we pray this in Jesus' name, and we encourage you to always use the power of this name in prayer. If you have not already believed in Jesus Christ then please acknowledge your sin and believe in His death on the cross as payment for your sin and His resurrection as your justification before God.
Marriage is a sacred institution ordained by God, and it should be entered into with reverence and sobriety. It is a lifelong commitment between a man and a woman, and it should be built on a foundation of mutual love, respect, and a shared faith in Jesus Christ. As it says in Ephesians 5:25, WEB, "Husbands, love your wives, even as Christ also loved the assembly, and gave himself up for it."
Regarding your situation, it is concerning that you mention she does not feel anything for you. While feelings can grow over time, it is important that there is a foundation of mutual respect and affection. Love is not merely a feeling, but a commitment and a choice. As it says in 1 Corinthians 13:7, WEB, "Love bears all things, believes all things, hopes all things, endures all things."
We also want to address the issue of communication. It is important that you both communicate openly and honestly with each other. It is not healthy for one person to be the only one initiating contact. As it says in Ephesians 4:15, WEB, "but speaking truth in love, we may grow up in all things into him, who is the head, Christ."
We encourage you to spend time together in prayer and in the study of God's Word. This will help you both to grow in your faith and in your relationship with each other. As it says in Psalm 119:105, WEB, "Your word is a lamp to my feet, and a light for my path."
Let us pray for you:
Dear Heavenly Father,
We come before You today in the name of Jesus Christ to lift up our brother and his upcoming marriage. Lord, we ask that You would soften her heart and help her to feel his love and to love him in return. We pray that You would help them to communicate openly and honestly with each other, and that You would build a strong foundation of mutual love, respect, and faith in Jesus Christ.
We rebuke any spirits of discord, misunderstanding, or manipulation that may be at work in this situation, and we ask that You would fill them both with Your love, Your peace, and Your wisdom. We pray that their marriage would be a testimony to Your goodness and Your grace, and that it would bring glory and honor to Your name.
Lord, we also pray for their spiritual growth, that they would both be rooted and grounded in Your Word, and that they would walk in Your ways. We ask that You would bless their marriage and that You would use it for Your purposes.
In Jesus' name, we pray. Amen.
We encourage you to continue to seek God's will for your life and for your marriage. Trust in Him, and He will direct your paths. As it says in Proverbs 3:5-6, WEB, "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."
Prayer Focus: God, Thank You for loving me. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. 
