We understand your struggle with guilt and your desire to be forgiven. First, let's remember what the Bible says about forgiveness and redemption: "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).
Your past actions, including fornication, adultery, and homosexual behavior, are indeed sins according to the Bible (1 Corinthians 6:9-11). However, the good news is that God offers forgiveness and redemption through Jesus Christ. It's not too late for you. Jesus said, "All things are possible for him who believes" (Mark 9:23 WEB).
To forgive yourself, you must first accept God's forgiveness. Confess your sins to Him, turn away from them (repent), and trust that He has cleansed you. Remember, "As far as the east is from the west, so far has he removed our transgressions from us" (Psalm 103:12 WEB).
About your fear of not being able to maintain a relationship, remember that God can strengthen you. "I can do all things through Christ, who strengthens me" (Philippians 4:13 WEB). Pray for God's guidance as you seek a relationship with a woman, keeping in mind that it should align with biblical principles, ultimately leading to a godly marriage.
Let's pray together:
"Dear Heavenly Father, we come before You, confessing our sins and seeking Your forgiveness. We believe in Jesus Christ, Your Son, who died for our sins and rose again for our justification. Please cleanse us from all unrighteousness, help us to forgive ourselves, and guide us into a future that honors You. Give us strength and wisdom as we pursue godly relationships. In Jesus' name, we pray. Amen."
Going forward, fill your mind with God's truth, immerse yourself in His Word, and surround yourself with a supportive Christian community. God has a good plan for your life, and He can turn your struggles into testimonies of His grace and power.