Overnight fame in the mid-noughties led Nash to a nervous breakdown and bankruptcy. Now, with a documentary capturing that harrowing time and a new career as an actor, she talks about the dangers young musicians face

Late in 2017, an article appeared on Buzzfeed with the headline: “33 Singers That Only Exist in the Mind of British Millennials”. At No 9 was Kate Nash, the mid-noughties MySpace sensation who had a huge hit with Foundations and went on to win best British female at the Brits. The article explained: “She was the cute vintage-dress-wearing girl we all wanted to be back in 2007. Presumably these days she’s wearing baggy jumpers and DMs, but who knows?”

The article touched a nerve with Nash. Not long before it was published, she had been having a teeth-gnashing, snot-in-the-hair breakdown in Death Valley, California. Dropped by her label, in dispute with her manager, she was left bankrupt, broken, wailing at the “wankers” in the music industry. “This is a matter of life and death to me because making music keeps me alive – and being in the music industry has almost killed me,” as she put it.

That moment is captured in the documentary Underestimate the Girl, which went up on the BBC3 iPlayer channel at the end of June and has won Nash a wave of support. “What I’ve really loved is seeing my fans being really emotional about it,” she says. “Musicians have been messaging me saying: ‘Oh my God, I was in tears watching this, the same thing happened to me.’ I think a lot of musicians are in this same situation.”

I meet Nash at her favourite vegan cafe in Hackney, east London. She wears her red hair in bunches as she did in the MySpace days – but the slouchy sweatpants, vest top and toned physique suggest a new steeliness. That is partly due to her training regime for Glow, the Netflix wrestling comedy that has helped her recent career move into acting. But it also reflects someone who has learned their lessons the hard way.

Nash stresses that the documentary was never supposed to be so raw. She was approached by the director Amy Goldstein after a performance at Coachella in 2014, when Nash was spending her own money touring the punky songs from her self-released album Girl Talk. The intention was to make an upbeat, vaguely empowering story about a kooky English musician moving to Los Angeles and making a comeback. It became a kind of millennial female version of the Bros documentary, with Nash forced into ever more humiliating compromises to make her music. But the “shit really hit the fan” when she discovered that what money she had managed to scrape together had been spent, leading to a total breakdown in her relationship with her new manager, Gary Marella. “I guess I just decided to keep filming because I felt like it was a really important story to tell,” she says. While it is a personal story, it has a wider resonance, capturing the collapse of the music industry.

Now 32, Nash was signed to Polydor when she was 17, in the wake of Lily Allen’s MySpace success. She recorded her first songs in her bedroom in Harrow, north London after a broken foot put paid to her job at Nando’s and her fresh-faced eclecticism earned her a young and dedicated fanbase. When I ask who she was influenced by, she ranges freely among Celine Dion, the Spice Girls, Nirvana, Misteeq, the Beatles and UK garage, before alighting on the Buzzcocks. “They were the band I first got into that helped me write songs. I was like: ‘A-ha! You can just talk about working in River Island or whatever.’”

MySpace, she reckons, represented a brief window in musical history when teenagers genuinely took control. “It was kids putting music on their pages, other kids listening to songs over and over, people from the labels messaging people like me. MySpace was so punk. That’s probably why it got shut down – the industry was like, this can’t happen because we’re not in control.”

Facebook Twitter Pinterest Nash in Glow. Photograph: Erica Parise/Netflix/Kobal/REX/Shutterstock

But her success was wildly disorienting and she signed her record deal in a state of extreme anxiety. “My mum was like: ‘Look, if you don’t want to do it, we can just get on the tube, go home and go to Pizza Express and forget about it.’ And she meant it. But afterwards, my manager at the time said to her: ‘Well played.’ And my mum was like: ‘Excuse me? I’m not playing my own child!’”

But everyone else was playing her. Polydor worked her relentlessly: she toured for two years straight and ended up having panic attacks. Meanwhile, the tabloids were experimenting with their own new business model; stories about Nash having a pimple (or similar) made regular appearances in sidebars of shame. Nash is amazed that she had no pastoral care whatsoever. “Artists often have mental health issues. And their lifestyles are unstable because of all the travelling and the media commentary on their lives. Now I’m like: ‘How were all these 40-year-old men hanging out with me and happy to profit from me and not concerned about my health in any way?’”

After her second album flopped, Nash began channelling her rage into her music. In 2012, she uploaded a thrashy new track called Under-Estimate the Girl and was duly dropped by her label. NME’s headline was: ‘Kate Nash has committed career suicide – and it sounds amazing.’ She maintains it was the best thing she ever did. But it is one thing finding your voice, and another making money from it, as she discovered when she moved to LA.

This is where the documentary picks up the story – and at times, it all becomes a little cringe-making, especially when Nash starts rapping. There is an excruciating scene at an advertising agency, where Marella persuades Nash to perform a lunchtime gig in the hope of securing some influencer cash. “That’s the kind of thing I was doing all the time,” she laughs. “If you’re on an indie label, you’re not getting enough money. And if you’re on a major, you’re not getting enough support.” Marella also landed her a publishing contract, but she hated being part of a pop production line. “Those places are so weird. Someone comes up with a word like ‘volcano’ and then everyone makes loads of metaphors about love being like lava and stuff.”

After her Death Valley breakdown, she went home to her parents’ house, but she still had a tax bill on her publishing deal to pay and mounting legal fees. Ultimately, she had to sell the flat she had bought with the money she had earned early on in her career. “I remember being at mum’s house and lying on my sister’s bed for some reason and I was frozen and I couldn’t even cry any more. When I had to sell my flat, I was like: ‘I’m an idiot, I make terrible decisions, I’m attracted to all the wrong people. I can’t do this because I’m too naive and too open-hearted, I trust people too quickly. But I can’t become hardened, I don’t even know how to do that.’”

The film could easily have ended with Nash going back to Nando’s. But eventually she found a resolution. “You have to go: ‘Why do I want to do this? It’s torturing me, it’s really painful, I’m on the edge, why do I need to continue?’ But this isn’t a choice, this is who I am.”

The stars somehow aligned: a successful Kickstarter campaign reconnected her with her fans; a surprise callback from Netflix opened up new horizons. But she has still faced two years of financial upheaval and legal machinations. Marella offered to settle three-quarters of her claim out of court but she decided to take the risk of going to court as she wanted to “look him in the eye”. Eventually she settled her claim outside the court doors and was happy with the outcome. Marella is still in the music business and recently took on Timbaland as a client.

Facebook Twitter Pinterest Nash onstage in LA this year. Photograph: Scott Dudelson/Getty Images

Nash’s experience in Glow has not only taught her some useful wrestling skills; it has also showed her that creative industries can be professional and unionised. “As many problems as there are with Hollywood, I feel so much more protected because if there’s a serious issue, I have someone I can talk to. Where’s that in the music industry? We need it. Because our lifestyles are associated with partying, it hasn’t had to be professional. But you’re like: ‘Where’s HR?’”

She feels particularly protective of young musicians starting out. “I always say: ‘Here’s my number, just call me.’ I have loads of artists that I’m in touch with that I’m always checking in on.” She has noticed more solidarity among musicians in recent years – she can’t think of anyone who looked out for her, though she did find a kind note from Annie Lennox when she was clearing out her bedroom the other day. She has also remained good friends with Sam Duckworth, AKA Get Cape. Wear Cape. Fly, who, like her, is now releasing music direct to his fans. “You have to find your own lane now,” she says.

Things seem to be looking up for Nash. She is in a relationship with an old schoolfriend, a hair stylist, who is about to move to LA with her. “He’s the first boyfriend I’ve had that’s like a really good person,” she laughs. “It turned into a bit of a Notting Hill romcom accidentally.” She is also in the Horrible Histories movie, out this summer. And the 10-year anniversary tour in 2017 of her debut album Made of Bricks reminded her why she got into music in the first place. She was initially surprised to see teenagers in the audience. But one fan explained that he listened to her when he was eight and she found this strangely touching.

“They are so honest with me because I’m honest with them,” she says. “My openness has brought in these special, fragile people, people who have troubles and are quite shy. I value that so much. This is why I’m not hardened.”

• This article was amended on 6 August 2019 to clarify that the court case which Nash brought was settled rather than going to a hearing as an earlier version suggested.

Kate Nash: Underestimate the Girl is available to watch on the BBC iPlayer