Teresa Reveles lived with Simmons for 35 years.

“I can’t stop crying.

I still can’t believe what happened,” Reveles toldPEOPLEin her first interview, published Monday.

Richard Simmons

Richard Simmons died July 13.Gregg DeGuire/WireImage

But when asked if she’d rather talk about her longtime boss and friend later, she flatly refused.

“No, I want to celebrate Richard,” she told the magazine.

“He died happy.”

The Los Angeles Fire Department said at the time of his death that it was fromnatural causes.

“That’s why I know it was a heart attack,” Reveles said.

“I had a heart attack a few years ago, and my hands did the same.”

“When he told me that, I thought,He’s kidding.

He can’t do that,” she recalled.

“But he said, ‘I want to be Richard.

And that’s why he did it.”

His last days were spent communicating with fans, she said.

He was also working on an ABC documentary about his life and a Broadway musical on the same topic.

“How do you deal with loss?

It takes a toll on your heart,” he read.

“Some shed many tears, others stare at the sky.

It’s so hard to say goodbye.

Later that day, Reveles said, he fell.

He wanted to wait one more day.