It's not up to you to better yourself. It's up to you to 'stay in step' behind God's Spirit as he betters you:
So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. For the sinful nature desires what is contrary to the Spirit, and the Spirit what is contrary to the sinful nature. They are in conflict with each other, so that you do not do what you want. But if you are led by the Spirit, you are not under law.
The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.
But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. Against such things there is no law. Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires. Since we live by the Spirit, let us keep in step with the Spirit. Let us not become conceited, provoking and envying each other. (Galatians 5:16-26,NIV)
I call this passage 'The Christians Code of Conduct'. At first glance it looks like a list of Do's and Don't's. But we need to look more closely at this passage in order to get its full message to us.
In the first paragraph, note that it is not you yourself that is fighting the sinful nature. It is God's Spirit that has engaged it in battle. None of us could defeat our natural selves anymore than a leopard could exchange his spots for stripes. So God has to do the fighting for us. What we are to do is permit the Spirit to 'take the lead', then follow behind him.
The second paragraph is a list of those 'acts of the sinful nature' that the Spirit is fighting. But notice how many of those acts aren't acts at all. They're the emotions which, if left unchecked, culminate in the performance of sinful acts. We need the direct action of God's Spirit to change the very core of our being, and that is where these emotions originate.
In the third paragraph is what the Spirit himself is doing in order to bring our natures into line with what he would have us do. When the Holy Spirit comes to dwell with us upon our having accepted God's gift of salvation, he does not come to us empty-handed. He brings with him the 9 'fruit' which he then implants in us. This we are to accept as our new nature, and because it too is almost totally based on core emotions rather than the performance, or the refraining from the performance, of a specific act, it depends on the actions of God himself rather than our own. So again we are told to 'stay in step' with the Spirit. What he does is the spritual equivalent of a heart trahsplant, and that requires his skill rather than our own.
Trust God to lead you forward. The fact that you recognize some of your thoughts and actions as being less than exemplery is a good sign. It shows that the Spirit is at work in you even as you read this message. Trust him, and have patience with yourself. You're in God's hands now, and he has a firm grip.