After returning to the United States, she has overcome the issue. "I have been to the gym and did a little bit of working out," she told People.
"It's frustrating because I can do everything again. I don't know ... the stress, anxiety, the build-up or whatever happened, happened."
Biles' withdrawal from the events in Tokyo added to the ongoing discussion about mental health in sport, and she hopes to keep that conversation going as she headlines the "Gold Over America" nationwide tour which begins next month.
Speaking to the Associated Press, Biles explained: "We wanted to make it as relatable as possible and let these kids know that we’ve been going through these things."
Biles: "It was like second nature again"
In Tokyo, having pushed through a few wobbles in qualifying, Biles pulled out of the team final after she was off on her opening vault.
She later explained she was suffering from the "twisties", a mental block where gymnasts lose their awareness in the air and are unable to control their skills or landing.
Back in Texas, she has been working with her coaches Laurent and Cecile Landi.
She told People: "(Laurent) was like, 'Okay well I need you to go on the [trampoline] and do a full-in, that's all I care about'.
"I started doing a couple fulls and on the first one, it was literally like second nature again."
Biles giving back to gymnastics communities with tour
Biles' withdrawal in Tokyo sparked global support for the Texan gymnast.
"I wouldn't change anything for the world," she said to AP.
"I gave an outlet for athletes to speak up about their mental health and their well-being and learn that you can put yourself first before the athlete."
The Gold Over America tour, which begins 21 September in Tucson, Arizona, aims to continue that.
Biles's Tokyo 2020 "Fighting Four" compatriots Jordan Chiles and Grace McCallum as well as fellow Tokyo medallists MyKayla Skinner (vault silver) and Jade Carey (floor gold) will join her, with Olympic all-around champion Sunisa Lee perhaps making guest appearances if college allows.
The tour visits 35 cities across the United States before ending in Boston on 7 November.
"This will be an amazing time to give back to our communities because they've been so supportive and loving to us," Biles said.