If you want to kill your sin only because you fear its consequences, then you are not going to succeed. If you want to be freed from a sin only because it keeps you from getting something else you want, then you will only exchange one sin for another.
If your motivation in repentance is anything other than fear of and love for God, then you will give up before you even begin. If your aim is anything short of the glory of Christ, then you will completely and utterly fail. If your trust is in anything other than the power of the Holy Spirit, then you have no hope of changing.
God sees into the hearts of all men, and He judges their thoughts. Mere outward lifestyle change is not enough to appease God’s wrath. There is forgiveness through Christ, who was punished in your place. Cry out to God with the voice of your heart, and He will hear you!
“’Yet even now,’ declares the LORD, ‘Return to Me with all your heart, and with fasting, weeping and mourning; and rend your heart and not your garments.’ Now return to the LORD your God, for He is gracious and compassionate, slow to anger, abounding in lovingkindness and relenting of evil” (Joel 2:12-13 NASB).