She has spoken about the trauma of the Manchester terror attack two years ago, saying there is a lot she will "probably never be ready to talk about".
The US pop star had just finished a concert at the Manchester Arena in May 2017, when a suicide bomber killed 22 people at the venue.
Grande has said in an interview that she struggles to talk about it even now, because her thoughts are with the families affected.
The 26-year-old singer told Vogue: "It's not my trauma. It's those families.
"It's their losses, and so it's hard to just let it all out without thinking about them reading this and reopening the memory for them."
Grande, who held a huge fundraising concert at Manchester's Old Trafford cricket ground following the attack, said that she feels she did "nothing".
She said: "I'm proud that we were able to raise a lot of money with the intention of giving people a feeling of love or unity, but at the end of the day, it didn't bring anyone back.
"Everyone was like, Wow, look at this amazing thing, and I was like, 'What the f*** are you guys talking about?'
"We did the best we could, but on a totally real level we did nothing. I'm sorry."
The One Last Time singer added: "I have a lot to say that could probably help people that I do want to share, but I have a lot that I still need to process myself and will probably never be ready to talk about.
"For a long time I didn't want to talk to anyone about anything, because I didn't want to think about anything. I kind of just wanted to bury myself in work and not focus on the real stuff, because I couldn't believe it was real."
Grande, who over the past year has also dealt with the death of her ex-boyfriend Mac Miller, and the breakdown of her engagement with the comedian Pete Davidson, also said she was "the luckiest girl in the world, and the unluckiest".
The performer said: "I'm walking this fine line between healing myself and not letting the things that I've gone through be picked at before I'm ready, and also celebrating the beautiful things that have happened in my life and not feeling scared that they'll be taken away from me because trauma tells me that they will be, you know what I mean?"
Miller died in September 2018 and Grande said that she can barely remember the months following, "because I was (a) so drunk and (b) so sad".
© Sky News 2019