Repentance is not a piecemeal operation. It is not possible to repent of a single sin.
For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all. (James 2:10)
God cannot forgive sins singly; you either obey all of the commandments you know or his sacrifice does not apply to you.
And if ye believe on his name ye will repent of all your sins, that thereby ye may have a remission of them through his merits. (Helaman 14:13)
For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins, (Hebrews 10:26)
Obedience to God is a binary attribute. You either obey all you know from God, or you don’t. It is not possible to be partially obedient to God. You are either fully submitted to him or you aren’t:
...a man being a servant of the devil cannot follow Christ; and if he follow Christ he cannot be a servant of the devil. (Moroni 7:11)
You must bring your life into complete alignment with your sincere understanding of what God would do in your place at all times and in all places.
Those who don’t obey everything they know about God, all the time, cannot go to heaven.