A lot of people are carrying emotional baggage around with them. And what I mean by emotional baggage is guilt from things that they've done wrong in the past. Jesus said, "Come to Me, all you who labor and are heavy laden, and I will give you rest" (Matthew 11:28 NKJV). Jesus wants to give us rest from our burdens. Therefore, we have assurance that if we go to Him He will give us rest; He will set us free from the guilt that binds us to the past, and put us on a path that leads to life everlasting.
God is love. And there's nothing that we can do to stop Him from being what He is. His grace is sufficient, inexhaustible, and all encompassing. His mercy endures forever. If He says you are forgiven then you are exactly what He said you are. Why assume the worst when the worst is not a part of your experience? Step into the new life that Christ offers you and be free from guilt. There is no condemnation in Christ.
Perhaps you feel that you've gone too far, that you have moved beyond the point of no return. I assure you that if that is how you feel then you aren't thinking right about God. God's arms can reach you wherever you're at. You can't go so far away as to escape His sight. He is everywhere. And He knows your heart better than you do. The door of opportunity for forgiveness is opened wide. He's waiting for you to walk through it. Simply acknowledge your sin, repent of it, and accept His grace.
God is not out to hurt you, but rather to embrace you. He doesn't want to put you down, but desires to lift you up, and put you on solid ground. He wants to usher you into a better life. Let Him do that for you. Let Him show you how great His love for you is. Cast those burdens of yours on Him. Don't live in the past, but step forward and abide in Christ. There's nothing that you can do to change the past. Accept that, and move on with your life. God loves you. Believe that by accepting His grace.