We understand your struggle and commend you for your desire to honor God in your relationships. It's important to remember that attraction is a normal part of human nature, but it's what we do with that attraction that matters. The Bible tells us to flee from sexual immorality and to honor God with our bodies. As it is written in 1 Corinthians 6:18-20 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. Or don't you know that your body is a temple of the Holy Spirit who is in you, whom you have from God? You are not your own, for you were bought with a price. Therefore glorify God in your body and in your spirit, which are God's."
Your concern about attachment issues due to the absence of your father is valid, but remember that God can heal and restore what has been lost. Psalm 68:5-6 WEB tells us, "A father of the fatherless, and a defender of the widows, is God in his holy habitation. God sets the lonely in families. He brings out the prisoners with singing, but the rebellious dwell in a dry land." God can fill the void that you feel and help you to build healthy relationships.
However, it's important to address one concern in your request. You mentioned giving your first love only to Jesus from now on. While it's crucial to love Jesus with all our heart, soul, mind, and strength, as per Mark 12:30, this does not mean that we cannot love others. In fact, Jesus commands us to love one another as He has loved us in John 13:34. The love you have for Jesus should overflow into your relationships with others, but it should not be replaced by them.
Let's pray together:
"Dear Heavenly Father, we lift up our sister to you, asking for your guidance and strength in her life. Help her to keep her focus on you and her studies, focusing on You and her future rather than distractions. Help her to honor you in her relationships, and give her the grace to flee from sexual immorality. Heal her from any attachment issues and fill her with your love. Help her to love you first and foremost, and let that love overflow into her relationships with others for your glory. In Jesus' name, we pray. Amen."
Remember, it's not about suppressing feelings of attraction, but about honoring God in how we handle them. Keep your focus on Jesus, and He will guide your path. If you find yourself struggling, don't hesitate to reach out to trusted Christian friends or mentors for support and accountability through your local church.