Mya-Lecia Naylor died by misadventure after hanging herself at her family home, a coroner has ruled.
Emergency services responded to reports of the 16-year-old in cardiac arrest in a marquee at her home in South Norwood on 7 April.
She was taken to Croydon University Hospital, but was pronounced dead a short while later.
Her father Martin told South London Coroner's Court that his daughter "had not been her normal self" and had been "stressed about her [GCSE] exams", which she was due to sit earlier this year.
She had recently discovered from her school that her grades were lower than expected.
Mr Naylor added: "She knew she needed to get on with her revision and she had plans scheduled out for her revision."
The Millie Inbetween and Almost Never star had also been grounded and stopped from attending a party, and had spent the evening before her death watching a film with her family that included a suicide scene.
Mr Naylor said he believed his daughter did not mean to take her life, and that she had made a "silly mistake" while "making some sort of point".
He said: "I genuinely believe she did not mean to do it. It was a silly spur of the moment thing. She clearly had plans for the future."
Days before her death, the 16-year-old had talked in an interview with Tresa magazine about wanting to get back into posting weekly videos to her YouTube account after sitting her GCSEs.
She also expressed an interest into exploring more work on the radio.
"It's really hard at the moment since I've got my GCSEs in about two months, but as soon as that's over, I really want to get back into the habit of posting on YouTube weekly and really engaging that," she told the magazine.
Back in April, CBBC released a statement saying the teenager was a "much loved part of the BBC Children's family" and a "hugely talented actress, singer and dancer".
Emily Atack, her co-star in Almost Never, said she was "shocked and sad" upon news of the teenager's death, recalling the "beautiful and talented" actress that was a "complete joy to be around" on set.
Alice Webb, director of BBC Children's which includes CBBC, said the team was "distraught and so terribly sad" to hear the news.
She added: "She has shone so brightly on our screens, both in Millie Inbetween and Almost Never, and it's unthinkable that she won't be part of our journey going forward.
"She was hugely popular with our audience, a very talented actress, dancer and singer, and a real role model for her young fans."
Mya-Lecia landed her first acting job on television for one episode of Absolutely Fabulous when she was just two years old.
She also appeared in Cloud Atlas alongside Tom Hanks and Halle Berry in 2012.