If you’ve visited a bookshop in the last few years, you would have found it hard to avoid a tanned and lean Sarah Wilson beaming out at you from the covers on the front shelves. Her cookbooks, I Quit Sugar and Simplicious, have been bestsellers, and her name is synonymous with terms such as “clean living” and “vitality”.

Wilson’s latest book couldn’t be more different. The cover is dark blue, with an illustration of a gloomy octopus – even the title itself seems like something from a poetry collection with a small print run.

First, We Make the Beast Beautiful is the story of Wilson’s struggle with anxiety – and it is a harrowing, sometimes claustrophobic read. The writing has an intensity reminiscent of journal entries, and the reader, brought close to Wilson’s pain, is liable to feel slightly anxious too.

Anxiety is not a new thing in Wilson’s life. In the book we shuttle back and forth between time periods: there’s Wilson at 13, taken to see a counsellor for insomnia; there she is as a teenager, discovered in a shopping centre and encouraged to model but feeling different and separate from other girls; there she is in Santa Cruz as a university exchange student having a breakdown and returning home, only to be diagnosed with bipolar disorder. There are the fast, high-pressure years editing Cosmopolitan magazine and self-medicating with a bottle of wine a night, followed by her time on MasterChef, when she was trying to cope with an increasingly debilitating autoimmune disease.

Now, aged 43 and a successful entrepreneur with her I Quit Sugar program (it’s not just a program but a mini-industry), the anxiety has come along for the ride. But lately she has been thinking differently about it, wondering if it can actually be a force for good – if she has found success because of, not in spite of, her anxiety. This is the act of “making the beast beautiful”, a departure from the usual positive-thinking literature, which encourages people to overcome adversity, rather than Wilson’s tactic of embracing it.

“There have been a lot of successful people throughout history who have had anxiety – including people like Churchill,” Wilson tells Guardian Australia. “If you look at the history of writers and entrepreneurs, many have some sort of anxiety disorder. I thought it was time that we [had] a new conversation around it.”

The idea for a book about anxiety came to Wilson a couple of years ago when she was on a panel at the Melbourne writers’ festival: “I was talking about sugar but all the questions were about anxiety. People are desperate to have a deep and proper and real conversation about anxiety.”

She admits wanted to tell her own story, “because I am sick of feeling lonely”.

“Anxiety is a very lonely condition but I feel like there’s a yearning out there to connect over it,” Wilson says.

Since the book was published at the end of February, Wilson has been swamped with people writing to her about their own issues with anxiety, or the anxiety of loved ones.

“The feedback and engagement has indeed been overwhelming. I’m receiving hundreds, sometimes thousands, of emails, tweets, letters, texts and calls every day,” she wrote this week on her blog.

The number of people reporting anxiety-related problems has risen sharply in Australia over the past few years, from 3.8% of the total population in 2011–2012 to 11.2% in 2014–2015, according to the Australian Bureau of Statistics.

Wilson divides the experience of anxiety into a couple of camps. “You have this thing I call ‘fair enough’ anxiety, which a lot of people experience. It comes from things like public speaking or going through a divorce. Then you have disordered anxiety – and that can overtake your life. There’s not a rational trigger – it’s in your cells, it’s in your bones.

“Everyday anxiety is on the increase and the things that are part of modern life drive it. We are in a permanent state of frenetic, highly agitated states of being; not getting enough sleep, rushing, too much work, not enough balance – stressful conditions. We’re emulating anxious conditions in our everyday living. It’s in how we applaud A-type behaviour.”

Wilson is still rolling with the punches. The book doesn’t sugarcoat life with anxiety, and its final chapters deal with Wilson suffering a miscarriage and a relationship breakup. She even notes, almost casually, that during the time she wrote the book, she attempted suicide twice.

Readers, particularly those who only knew the beaming, sugar-free Wilson from her cookbooks, might feel quite concerned for her.

“I was very honest about detailing self-harm,” Wilson says. “Nobody talks about the really ugly stuff.”

Is she going to be OK?

“I do have anxiety and I have a good life,” says Wilson. “I would not have my business if I did not have these [anxious] episodes. In terms of my business, I have a GM in place and I have a team and I set it up so they don’t rely on me. And each year that passes my hands-on operational work reduces and reduces. In order to manage my anxiety I have to put in place healthy practices. It has enabled me to disappear and live in an Airbnb at the beach, or to travel or take off hiking whenever I need to.”

Anxiety can be managed, says Wilson. “You just have to find your path with it.”

• First, We Make the Beast Beautiful by Sarah Wilson is published by Pan Macmillan

• Crisis support services can be reached 24 hours a day: Lifeline 13 11 14; Suicide Call Back Service 1300 659 467; Kids Helpline 1800 55 1800; MensLine Australia 1300 78 99 78