Whenever someone asks me a question like this I often think of Peter in the Bible. He was one of Jesus' closest disciples - and yet when Jesus was arrested, Peter turned his back on Jesus and loudly announced that he didn't even know Him (see Luke 22:57).
But later Peter realized what he'd done, and he came back to Jesus. And what did Jesus do? Jesus forgave him and welcomed him back as one of His disciples. Later, Peter became one of the strongest spiritual leaders of the Early Church, and God used him to bring many people to Christ. He even was willing to risk death for the sake of Christ, and tradition says that later Peter actually was killed for his faith in Christ.
Yes, it would've been better if you had never turned away from Jesus. But listen: God still loves you, and Christ died for you. God's promise of forgiveness is for all who know they need Him: "If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness" (1 John 1:9).
Don't let another day go by without Christ, but confess your sins to Him and ask Him to be your Savior and Lord. Then ask Him to help you walk with Him every day - through prayer, the Bible, and fellowship with other believers.