"I'm sad, I'm disappointed, I'm angry — I can't. I'm really upset, I think I cried for about two days," the British singer told Sway.
Estelle, who frequently crossed paths with Winehouse during the pair's rise across the pond and then here in the States, steered clear of any judgment concerning Amy's documented battles with drugs and alcohol. While it has been widely speculated that Amy's addiction led to her death, an initial autopsy reportedly came up inconclusive.
"Amy's been Amy — that's Amy, a bit drunk, a bit high. My thing is, again, you can't tell from the inside-out what is going on with an artist," Estelle said. "This fame is a juggernaut: It slaps you in the face and you don't know what you're doing. You don't know who has your back, who is your support system."
Estelle, who won a Grammy in 2009 for her single "American Boy," knows the pressures that being in the spotlight can bring and said she didn't want to condemn anyone for how they deal with it.
"I don't want to judge her, having similarly been through that explosion of everything, [becoming] famous all at once," she said. "And then having to deal with my stuff in public in front of people that I never knew and I know don't care about me and are just after whatever they are going to get from me.
"It's hard," Estelle said before getting a bit choked up. "We came out with albums at the same time, so I'd always see her. I just know she deserved better than that."
Catch MTV's Sway on "Sway in the Morning," on SIRIUS XM Radio's Shade 45, Monday through Friday, from 8 a.m. to noon ET.
Celebrate Amy Winehouse on Wednesday night (July 27) at 6:30 p.m. ET/PT, when MTV will air an encore presentation of a performance she taped in the MTV studios in 2007.