Let me ask you a question: Have you ever read the greatest book that was written on how to become a better person? That book is the Bible–and if you've never read any of it, I urge you to do so.
Why do I say this? The reason is because the Bible isn't just another book on self-help. In fact it isn't a "self-help" book at all because it tells us that we are too weak to change our lives and make ourselves into the kind of people we ought to be. We may not like to admit this–but it's true, as you know from your own experience.
Instead, the Bible points us to God, for only He can change us and make our lives different. We can't change our lives–but God can, and He will if we let Him. God loves us, and He doesn't want us to be sunk in a pit of helplessness and despair the rest of our lives.
How does this happen? It begins with repentance–telling God we know we have sinned, and we are turning from our old ways of living. Then we must turn to Jesus Christ and ask Him to come into our lives as our Savior and Lord. When we do, God Himself comes to live within us by His Spirit. Then we'll discover the same truth the Apostle Paul discovered: "I can do everything through him who gives me strength" (Philippians 4:13).