"I'm almost incapable of talking about this still," Mariah said on GMA. "It's very heavy emotionally."
Mariah also revealed what it was like working with the legendary icon:
"It was great and I don't think people could ever understand our relationship. There was always this supposed rivalry in the beginning and then we did the duet and we became friends."
It's a sad time for Mariah, who collaborated with Whitney Houston on their beautiful ballad, "When You Believe."
The mother of twins also told GMA that the service "was gorgeous, the way she went out and the way family dealt with it, I was very moved."
We couldn't agree more.
Watch Mariah get personal in the video below.