Admitting that it's now been two-and-a-half years since she last had a drink, she said it wasn't so easy in the beginning.
"So those first days I felt like a junkie, the way the cravings came on and I wanted to drink and the embarrassment of it, of being that person, that thirsty b**ch," she said in her open letter.
But she encouraged those who are trying to give up booze to push on.
"I think if you can make it through the first two weeks, you're in with a chance.
"So I made it through, and it's been two and a half years," Yumi explained.
The mum-of-three said she'll never go back to drinking again and her sobriety has given her a new zest for life, having accomplished goals she never thought possible.
"I have written and published three books and am working on my fourth.
"I've fronted a hugely successful podcast that focuses on two of my passions — women's health and empowerment.
"I've reached fitness goals I never would've believed possible," she exclaimed.
And she had some final words of advice for anyone trying to quit the booze.
"I know your journey is your thing. No-one can do it but you.
"But if it helps, then please know that I'm watching from over here and I'm cheering you on."