Let me ask you a question: When Jesus died on the cross, how many of your sins did He take upon Himself? Did He only die for the ones you can remember? Or did He die for all of them–even the ones you can't remember, and the ones you didn't even realize were sins?
I think you know the answer. Jesus didn't die just for the sins you can remember; He died for all of them! Think of it: He was perfect and without sin–but every sin you ever committed was placed on Him, and He died in your place. The Bible says, "If we walk in the light, as he is in the light ... the blood of Jesus, his Son, purifies us from all sin" (1 John 1:7).
In other words, when we come to Christ and trust Him alone as our Lord and Savior, God forgives us totally and completely. He doesn't forgive us halfway, or three quarters of the way–He forgives us all the way! He doesn't do this because we have earned it, or because we deserve it, but simply because He loves us. The Bible says that because of what Christ did for us on the cross "we have redemption through his blood, the forgiveness of sins" (Ephesians 1:7).
Ask Christ to come into your life and forgive you right now–and He will. Then thank Him for forgiving you of all your sins, and ask Him to help you by His Spirit to gain victory over sin every day as you yield yourself to Him.