The 30-year-old Springboks loose forward captained the side that defeated the All Blacks 31-29 on the Gold Coast on Saturday.
Kolisi, whose new book 'Rise' is due out later this month, also led South Africa to the 2019 World Cup as skipper, having become the country's first black captain in 2018.
The 56-cap veteran, who debuted internationally in 2013 as a 21-year-old, revealed the struggles prior to his rise and throughout his career.
"Some people also know how I was in the past and I’m not a saint at all. I’m a sinner trying to be the best he can be every day," Kolisi said.
"I drank when I was happy or sad, or dealing with something. Drinking was the only way I knew to get through this stuff."
He said: "Let’s say I’m someone’s role model. The kid will think: ‘I want to be like you one day.’ But he doesn’t know the struggles you face. No one tells him there’s temptation – alcohol, drugs, all these things are available to you.
"I wish I’d had a mentor that told me you’re going to face these challenges and you must be prepared to fight them.
"I had to go through the hard way. Now I want to make sure the next kid and his family can read the book and think: ‘How will we prevent that? How will we prepare you for that kind of life?'"
Kolisi, who is a devout Christian, revealed his gender-typical struggle with articulating himself, using alcohol, strip clubs and pornography to escape his confusion.
"I didn’t know how to speak for a long time," Kolisi said. "I’m learning as I go along with my wife.
"We’re five years into our marriage and I’m still learning how to have a proper conversation with her. That’s why I put in [the book] the things I did in the past, some of the vulnerability, so it can tell the true story."
Kolisi also spoke about his upbringing in Zwide, a township outside of Port Elizabeth, and losing his mother when he was 15, having seen her beaten by men. He has utilised his profile to be an advocate for gender equality.
"You win the World Cup and get given a platform. [Kolisi's wife] Rachel said: ‘You couldn’t help your mother or your aunt but you can help other women.’ She was right," he said.
"Gender violence hurts me even if I am a man. I have my own daughter, my wife and my sister. I would never want them to suffer this violence."
On pornography fueling gender violence, he said: "I’m not a professional so I don’t really want to get into that. But I know it [pornography] was a problem for me. I can’t say more than that."