Months after her highly-publicized withdrawal from the Tokyo Olympics, USA Gymnastics star Simone Biles has returned to the mat as a headliner in the Gold Over America Tour's all-star lineup of gymnasts. But she's returned from Tokyo a changed gymnast -- and one still reeling from a mental block that has prevented her from performing her most spectacular stunts.

During an appearance on "The Today Show" Thursday, Biles admitted that she is still "scared" to do gymnastics after she began to experience the twisties -- a midair loss of orientation -- during the Olympics. As those issues have continued past the Olympics, Biles is currently only doing her signature move in floor exercise.

"To do something that I've done forever and just not be able to do it because of everything I've gone through is really crazy because I love this sport so much," Biles said. "It's hard. I'm sorry. And I don't think people understand the magnitude of what I go through, but for so many years to go through everything that I've gone through having a front, I'm proud of myself."

Biles has been open about her mental health issues. Last month, Biles was among the gymnasts who testified at a U.S. Senate Judiciary Committee meeting, accusing the FBI of turning a blind eye to convicted sex offender Larry Nassar's crimes against USA Gymnastics athletes.

Biles was the only competitor in the Tokyo Olympics who had been abused by Nassar, and she cited the trauma of both his crimes and the FBI's botched investigation of the former team doctor as part of the circumstances that led to her withdrawal.

"One thing that helped me push each and every day was the goal of not allowing this crisis to be ignored," Biles said at the U.S. Senate Judiciary Committee meeting. "I worked incredibly hard to make sure that my presence could maintain a connection between the failures and the competition at Tokyo 2020. That has proven to be an exceptionally difficult burden for me to carry, particularly when required to travel to Tokyo without the support of any of my family."

In the midst of her mental health issues, Biles announced Thursday that she has become the chief impact officer and an investor in Cerebral, a mental health and telemedicine app.