It's never too late to turn to God, because God still loves us even when we are rebellious and want nothing to do with Him and He still wants us to become part of His family forever.
The problem is, the longer we turn our backs on God, the easier it becomes to stay away from Him and the harder it becomes to hear His voice. But your letter suggests to me that He is still calling you, and that down inside you know you need Him. Don't make the same mistake you made over half a century ago and turn away from Him again! Jesus said, "Come to me, all of you who are weary and carry heavy burdens, and I will give you rest" (Matthew 11:28, NLT).
How should you come to Jesus? First, come by faith, believing that Jesus came from heaven to save you from your sins by His death and resurrection. Second, repent of your sins, asking God to forgive you for turning your back on Him all these years, and telling Him that from now on you want to live for Jesus. Third, commit your life to Christ every day, asking Him to help you be His follower.
Thank God also for His patience with you, and for giving you a second chance to repent and turn to Him. Most of all, thank Him for Jesus, and for the hope we have of heaven because of Him.