We are truly saddened to hear about the situation you find yourself in, and we are here to pray with you and guide you according to God's word.
Firstly, we commend you for taking responsibility for your actions and recognizing that you have sinned. The Bible tells us, "For all have sinned, and fall short of the glory of God" (Romans 3:23 WEB). It is important to understand that sexual relations outside of marriage is fornication, which is indeed a sin according to the Bible (1 Corinthians 6:18 WEB).
However, God is merciful and forgiving. He promises us, "If we confess our sins, he is faithful and righteous to forgive us the sins, and to cleanse us from all unrighteousness" (1 John 1:9 WEB). We encourage you to confess your sin to God, ask for His forgiveness, and turn away from this sin.
We also want to address the stress and fear you're experiencing. God tells us, "Don’t be anxious for anything, but in everything by prayer and petition with thanksgiving, let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your thoughts in Christ Jesus" (Philippians 4:6-7 WEB). Cast your anxieties onto Him, for He cares for you (1 Peter 5:7 WEB).
Let us pray together:
"Dear Heavenly Father, we come before You today to lift up this young man and his girlfriend. Lord, they have strayed from Your path, and they are truly repentant. We ask for Your forgiveness and Your cleansing power in their lives. Lord, we also ask that You help them through this difficult situation. We pray that the girlfriend is not pregnant, as they are not ready for such a responsibility.
We ask for Your peace to fill their hearts and minds, Lord. Help them to trust in You and to lean on You for strength and guidance. In Jesus' name, we pray. Amen."
Remember, God loves you and He wants the best for you. He tells us to flee from sexual immorality (1 Corinthians 6:18 WEB) and to keep ourselves pure until marriage (1 Thessalonians 4:3-5 WEB). We encourage you to commit to this and to honor God with your bodies.
Lastly, we noticed that you did not mention the name of Jesus in your prayer. It is only through Him that we have access to God, and it is only through His name that we can be saved (Acts 4:12 WEB). We encourage you to learn more about Jesus and to put your faith in Him.