The retired basketball player was in a relationship with the "Keeping Up with the Kardashians" star from 2009-2013, and the pair wed just one month after they first met. In December 2013, however, the 34-year-old filed for divorce when she found out that the sportsman had cheated on her with several women.
Speaking in an interview with People magazine, Lamar, 39, shared his regret over how he behaved throughout the marriage.
"I wish I could have been more of a man," the star confessed. "It still bothers me to this day. But regret is something we have to learn to live with."
In excerpts from the NBA legend's upcoming memoir "Darkness to Light" shared by the publication, the star suggested that his battles with drug addiction ultimately led to his infidelity in the marriage.
"For a while, being with her was bliss and I was the happiest I've ever been," he wrote. "At the start of our marriage I was faithful to her... (but) I couldn't keep my d**k in my pants or the coke out of my nose."
Following the couple's separation, Lamar was hospitalised and near death following an overdose in 2015, and the Good American fashion mogul returned to his side to help him through his recovery.
Reflecting on the situation, Lamar lauded his ex-wife for her commitment to him at the time and shared his hope that the pair will be able to set aside their differences and one day be friends.
"Her love for me must have been unconditional. That's the only thing (I think) that gave her the strength to still love me at that time." he reflected. "I miss the family. And I hope we can all be reacquainted one day."
"Darkness to Light" will be released on May 28.