I am cautious about how much one can rely on a movie for biography; at times "artistic licence" seems to be a euphemism for "flagrantly disingenuous." Nevertheless, it told of his his addiction to (prescription) drugs and possibly alcohol; and his marriage break-up due to this and possibly his infidelity.
He subsequently recovered from his addictions and also married singer June Carter. He remained married to her until her death 35 years later.
The story reminded me of a prayer by a fellow parishioner. His own marriage had dissolved many years ago following his indiscretions. He subsequently remarried. He apparently prayed a few years ago during an open prayer meeting something along the lines of, "Lord, thank you that you are a God of second chances."
These are excellent examples of God's grace in people's lives. The God we serve is a God of redemption, of the returning prodigal, of mercy and goodness toward a race of sinners; a God of second chances.
As I live, declares the Lord GOD, I have no pleasure in the death of the wicked, but that the wicked turn from his way and live;... (Ezekiel 33)