Kim also revealed how he endured suicidal thoughts for nearly 20 years before turning his life around.
"Two years sober. Biggest accomplishment of my life," the 39-year-old Kim wrote. "I was barely physically able to walk into rehab needing assistance from my sober coach as my body was shutting down."
While on the PGA Tour, Kim said on Instagram he used drugs and alcohol every day to "numb the pain," hinting that the usage also happened during majors.
"I got so good at hiding it that I lost who I was," he said. "It's "f****n' hard playing majors making porta potty stops every few holes."
Kim played in 15 majors while a member of the PGA Tour from 2007-11, finishing as high as third in the 2010 Masters after a final-round 65.
He totalled five top-20 major finishes in that stretch, setting a Masters record in 2009 for most birdies in a round with 11 before finishing 20th.
A thumb injury in 2010 hampered his performance and led to him withdrawing from his final three tour events in 2012 and exiting professional golf.
After a lengthy absence, Kim returned to pro golf with LIV last year in his first start in the US in 12 years. Upon returning, he kept his struggles close to his chest, but opened up on Instagram about how much rehab helped him and how important every day is during his recovery.
"In rehab I found faith, self love and respect and purpose," he wrote. "I am not proud of who I was but I am today. One of the many things I realised is how grateful we all need to be for what we have now and to spend time with real friends because tomorrow is not guaranteed.
"I promised myself when I was in the ER for six days that I would do everything I could to make a difference to show my daughter that it's never too late to keep trying.
"I am currently working on a few things that I know will change peoples lives including a website where I will be sharing both good and bad experiences that hopefully others struggling can learn from."
Kim, who has finished T49 (Riyadh) and T51 (Adelaide) with LIV Golf this year, wants to encourage those battling with addiction to seek help and regain control of their lives.
"Not long before this moment I contemplated ending my life every day for almost two decades even while playing (on the PGA Tour), when I to the public seemed happy while struggling with addiction and mental illness," he wrote.
"This post isn't to tell everyone to get sober but for people who are letting addiction ruin their lives as I did that you can turn your life around."
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