Olivia Cooke felt "lonely and quite ill" when she lived abroad alone at a young age.
The 31-year-old actress moved from the UK to New York aged 21 - the first time she had lived away from her mum's house in Oldham, North West England - before going to Vancouver, Canada, and Los Angeles whilst filming multiple TV shows.
She explained in The Observer Magazine: "I was so career-focused back then, and I didn't really have a base.
"All my friends were here, and I didn't have many people around me. I was really lonely and quite ill."
But Olivia had to keep going because she was living her dream as an actress.
She added: "Who am I to say no?
"This was my dream come true, and I had nothing else to fall back on."
The House of the Dragon star - who almost lived off tuna pasta for years - said the experience was a "real awakening" into life as an adult.
Olivia said: "It was a real awakening into adulthood.
"I realise now just how young I was. In your early 20s, it's like being on a rollercoaster while trying to do mascara.
"It's a tough, lonely life, especially when you don't have the tools to look after yourself.
"It wasn't much more than a decade ago, but self-care wasn't really in our vocabulary. You unpack it later down the road in therapy when you're like, 'What is this malaise that I feel all the time?'"
The Girlfriend actress - who grew up in Oldham, just outside of Manchester, North West England - moved back to the UK aged 26 when the COVID-19 pandemic began.
Olivia - who never regarded the US as home - said: "Overnight, I felt way more centred and lighter.
"I'm a British girl who just loves a pub and a good hill walk."
Now living in London, the Game of Thrones star - who was rejected a place at the Royal Academy of Dramatic Art (Rada) aged 18 - feels happy to be settled.
Olivia said: "I feel like I was on a kind of pilgrimage from 18 to 26, so it's been nice to settle.
"I can feel my feet growing roots."
