The music icon tells PEOPLE she was “very, very nervous” to return to the Grammys stage

When Céline Dion made her big return to the Grammys in February to present the night’s biggest honor to Taylor Swift, the superstar was overcome with emotion.

“It was an honor for me that they thought of me to present to Taylor Swift. It was [her] fourth [time] winning this award, which is exceptional,” Dion tells PEOPLE exclusively in its latest cover story.

The “My Heart Will Go On” singer, 56, was accompanied onstage by her 23-year-old son, René-Charles, and having him nearby helped keep her calm.

“It was going to be my first time [back at the Grammys], and I didn’t want to feel wobbly. I was going to be very, very nervous and happy at the same time,” says Dion, who can enter a stiff-person syndrome crisis episode if her brain is overstimulated. “The applause… am I going to have a shock by seeing [the audience]? I didn’t want anything bad to happen.”

Since her SPS diagnosis in August of 2022, Dion — who shares her health journey in a new documentary, I Am: Céline Dion (streaming globally June 25 on Prime Video) — says she has largely stayed at home in her most comfortable sweats while undergoing treatment.

“Now I have heels and a dress that has a big opening on the leg, and I’m not sure if my legs are ready at that time,” she recalls of the Grammys. “It was a lot.”

But as she received a standing ovation from the audience, Dion felt right at home.

“When I felt that love, I had no doubt that [this is what] I miss and what I want. To see that I’m still in it and that they allowed me to be there… I enjoyed every moment,” says Dion. “I was so proud of my son asking me every two minutes before I was on stage, ‘Mom, are you okay?’ I said, I’m fine, I’m really fine.’”

Over the last two years, Dion has been following a combination treatment plan involving medication, immune therapy, vocal therapy and intense physical rehabilitation five days a week in hopes of making a return to the stage.

“I miss my fans tremendously. It’s a partnership. What I give, they give it back by their emotion that I see in their faces with their smiles, with their tears,” she says. “The curtain opens, and I feel the adrenaline. It’s pretty amazing after how many years that every time that curtain opens, I still feel that.”