The singer, who suffers from PTSD following the bombing of her Manchester Arena concert in May 2017, said she feels guilty about having anxiety "because it's just in your head" and though she wishes she could control it, "it's just so crazy how powerful it is."
"You have ups and downs and sometimes you’ll go weeks at a time where you will be crushing it and there will be no anxiety…and then something will happen that can trigger it and then you have a couple of down days," she continued.
Ariana said that the best piece of advice she can give to others who are suffering from mental ill health is to lean on loved ones around you.
"It takes hard work and practice and therapy and self-care - and so much love,” she said.
“It’s just in your head and it’s just so crazy how powerful it is...The most important thing is to remember that…everybody has this. Talk to your loved ones, reach out to people, especially your friends online."
The full special performance and interview will be available on the BBC website tomorrow.