Last November, Lola Young was finally having her moment. Messy, a track from her second album, This Wasn’t Meant for You Anyway, was blowing up on TikTok. Celebrities such as Kylie Jenner were using the track in their clips, and it had quickly permeated the barrier to the real world, becoming a staple of Uber rides and Christmas shopping trips in a matter of days. Even if you wouldn’t recognise Young if she passed you on the street, you’d know the song and its ironclad hook: “Cause I’m too messy! And then I’m too fucking clean … ”

Other stars might have taken a moment to enjoy the spoils, or strategise on how best to capitalise on the newfound success. But as Messy was rising in the charts, Young was checking into a rehab facility to deal with a cocaine addiction that had dogged her for “a long time”. By January, she was back doing Pop Star Things: performing on Graham Norton and Jimmy Fallon, performing a cover of a Cure song for an Australian radio station, and so on.

“It’s been a struggle – I’ve definitely had to work on some internal healing while grappling with touring and stuff,” she says quietly on a muggy afternoon in late August. “I’ve had to be away for a bit while battling with things. But it teaches you a lot, being addicted to substances. It makes you more empathetic about other people that have gone through that. It’s just a constant journey.”

Sitting across from me in a private room at Hide, a fancy restaurant in Mayfair, London, Young is an endearing mess of contradictions: she is timid, stuttering through the occasional phrase, and slightly combative, abruptly asking to change the subject whenever she feels she has said too much about a topic, even if she has barely spoken on it. She pairs her grey hoodie and gigantic camo cargo pants with a face that’s luminously made-up and studded in places I didn’t know you could get pierced. It is oddly fitting that we have met at a restaurant that plays Television’s 70s punk classic Marquee Moon over the speakers and serves a £90 prawn starter – and that, despite the restaurant’s Michelin star, we both stick to coffee.

This kind of contradiction is the lifeblood of Young’s third album I’m Only F**king Myself (asterisks hers). Released next week, it is a raw and raucous coming-of-ager that finds Young, 24, in a darkly comic battle with her vices: drugs, sex or simply talking too much shit. The frank sexuality of songs such as One Thing – a gentle, ribald afrobeat number – clashes with more raw fare such as D£aler, a skeletal road song about the alienation of addiction. Young says writing so openly about sex “was my way of masking” the hurt in the record. “It’s kind of, this is my alter ego, the sex thing – but underneath it is pain and aggression and things I was going through that were more difficult,” she says.

The result is a set of barnstormers such as the second track F**k Everyone, about wanting to “fuck guys who don’t like me”, that could set pop radio alight even as they touch on intense fear and self-loathing. “It can take you on a journey of like, OK, so she’s fucking everyone, but really, what does that entail? What does that really mean?”

Young grew up in Beckenham, south London. She played piano and guitar from her early years, and remembers “writing songs from a really early age”. She found school difficult, in part because of a schizoaffective disorder that she would be diagnosed with at the age of 17, and in part because of her time at her school, which she describes as “pretty, really, actually, really rough”. Young’s mother is white and her father is Jamaican-Chinese, and she was one of the only white-passing kids in her class. “I would fight to be like, ‘Look, I’m mixed-race,’” she says. “It’s complex being mixed race anyway, because you feel conflicted, and I’m very much aware of my privilege, not appearing as a person of colour. But it’s just been weird navigating it – I went through periods of hating my hair texture and being embarrassed of the food I was eating at home. It was a journey.”

A lot of that journey was informed by Young’s sister Becky, a campaigner with the music industry environmental charity EarthPercent who runs an anti-fatphobia Instagram page called Anti-Diet Riot Club. “She inspired me in every way – in like, what is feminism? What does it mean to be mixed race? What does it mean to be a woman living in London? I used to get my hair braided, and she was like, ‘No, you can’t do this,’” Young says. “I’ve learned a lot from her.”

In the past, Young says, she has felt the need to “prove” her mixed-race identity, which she doesn’t feel any more. “This is something that is so ingrained in me that I don’t feel the need to necessarily shout about it, you know? I’m Jamaican-Chinese. I’m very proud to be that,” she says. “Being aware of someone and noticing the difference is different to not accepting them, you know? I don’t give a fuck who you are, where you come from, what size, shape, colour you are. But I am aware of it, and what that means to them in society.”

In her teens, Young was accepted into the Brit school, the famed performing arts school attended by FKA twigs and Adele among others. She says it “had an incredible community and sense of friendship” that she had never experienced before. “I was coming from a school that was very like, the bullies were there: I was a bully, I’d been bullied. And I was walking into a school where that wasn’t an option,” she says. Even so, she still struggled with the formal environment. “I think people have this idea of Brit where it’s like, you’re standing on stage, it’s like Fame, and it’s just not like that. I still did all my regular subjects and was still shit at all of them and still fucking fought with teachers.”

At this point, Young had been busking and performing at open mic nights from the age of 14, but at the Brit school she realised that she loved being in the studio and working behind the scenes. For a moment, she thought she might want to be a songwriter rather than a performer. “I was like, you know what? I could do this – I could create and I could make people feel things through music,” she recalls. “If I can record a take 1,000 times, maybe this is me.”

Part of that desire, she realises now, comes down to the fact that it was the late 2010s, when it was woefully uncool to suggest that you wanted to get famous. “It was almost a bit arrogant, and growing up in London, British culture is quite like, you’ve got to dumb yourself down a bit. When I go to America, it’s like ‘Yeah, bro, I want to be famous’, and you see a nice car and it’s not a wanker [driving it],” she says. “But then I was like, you know what? Being famous is a byproduct of doing something well, in any field. Obviously, it’s been different than what I expected it to be, but I continue on the journey because I love doing what I do.”

Young seems hyper aware of this kind of stigma: she answers certain questions, including the ones about the Brit school, with the semi-defensive pose of an internet-born star who’s become used to receiving criticism about anything and everything. She says she “got loads of slander” about going to Brit even though “it’s in Thornton Heath! You just get in if you audition!” She’s realised that, as she becomes more famous, “You’re still just you, and nothing actually changes apart from online scrutiny.”

Earlier, I had asked how she felt about being called a “nepo baby” because her aunt Julia Donaldson wrote The Gruffalo. She declined to speak about it initially, but now she brings it up. “[People are] calling me a nepo baby even though they have no fucking clue who I am, they don’t know who I am, they don’t know what level of wealth I’ve come from, just because my aunt wrote The Gruffalo. I don’t think that’s a reason that I’m a nepo baby.”

Young was spotted by manager Nick Shymansky when playing open mic nights, and signed to Island in 2019. Shymansky managed Amy Winehouse until 2006, when “mental health wasn’t a conversation, addiction wasn’t a public conversation, and so people end up dying because they’re not open, they’re not able to seek help,” says Young. She says she feels “very grateful and appreciative” of the fact that she was able to work through her addiction with the help of a team that wasn’t judgmental of her, and with treatment facilities she could easily access. “A lot of people don’t have the privilege of being able to do that. A lot of people suffer from addiction, and a lot of people are in that personal journey [to recovery]. Anyone who knows that feeling will know it’s not linear, it’s always up and down, but it’s down to dysregulation of dopamine … coming out as ADHD as well and being diagnosed, that’s been hard to deal with,” she adds.

I suggest that casual drug use is normalised in the music industry. “Yeah, even more so it’s normalised in big cities – I don’t even think it’s just within the music industry,” she says. “It depends who you surround yourself with – you can always find [drugs], you know? It can be dark, it’s not always fun and party.”

Young says that the industry “can be a really dangerous place” for women. “It’s hard to be a female, let alone be a female in the industry … being in the spotlight, and having people, A&Rs or label execs wanting to mould you,” she says. She brings up Chappell Roan, who has faced criticism for trying to set boundaries around the way she expects to be treated by fans and paparazzi. “Everything she’s doing is perfectly feasible and right, and she got a lot of hate for being like, ‘Actually, you know what? I don’t want to do that, that’s not OK.’ People will respond by going, ‘Well, you wanted to be in the limelight’. But you don’t sign up to have cameras in your face 24/7.”

As well as addiction, I’m Only F**king Myself is preoccupied with sex – Young sings about hookups with a witty bluntness that feels more indebted to bawdy rappers such as CupcakKe or the hornbag producer Cash Cobain than any of her British pop peers. On One Thing, a skeletal earworm that’s vastly different from anything she’s made previously, she treats a man like her plaything, but in an endearingly casual way. “It was like, if a man can say ‘I’m only here for one thing’, so can I. But I also wanted to embody that feeling of not being constrained and constricted within sex,” she says. “It’s kind of me exploring things within myself and feeling sexy, but then also finding it hard to just have casual sex and it be brushed off.”

Right now, Young isn’t dating – she has just come out of a long-term relationship and is far too busy to consider it. She has already started working on the deluxe edition of I’m Only F**king Myself. After this bloodletting, fearless album – especially for an artist who’s in such an early stage of her career – she is “very excited to start talking about things that feel slightly more metaphorical” rather than stories that come directly from her diary. “I want to flip it on its head for the next one and create something that feels back to my roots of being a singer-songwriter,” she says, setting up her next contradiction.

• I’m Only F**king Myself is released via Island Records on 19 September