While Heaven may be the ultimate goal of a life devoted to Jesus, that doesn’t change the fact that obedience to God’s commandments, when done out of love, leads to the greatest life we can possibly have during THIS lifetime, too.
While sin may be pleasurable for a season, that season ends during THIS lifetime.
So, I would think one would want to enjoy this life to the fullest. The best way to do that is through loving obedience to God.
See John 10:10 (in part) “…I came that they may have life and have it to the full.”
As for hearing a voice that you are going to hell, God would not say something that denies His mercy and grace, and contradicts the teachings of His Church that are part of the Deposit of Faith.
So, no matter what you have done, God is still willing to forgive you if you make a sincere confession, and repent.