Kevin Costner and Whitney Houston shared career success in "The Bodyguard" and remained close friends after the 1992 film but it wasn't until Houston's surprise death in February that the actor realized the depth of the connection they shared.

"She was a very important person to me and the world has connected us in a way that we'll never not be," Costner said today on " Good Morning America."  "I didn't really get a full grasp of that until the lead-up to the funeral where people somehow felt that it was important that I say something."

Costner, 57, and Houston co-starred in the late singer's movie debut in which she sang "I Will Always Love You" in the film that made more than $400 million at the box office.  The actor delivered a moving eulogy at Houston's Feb. 18 funeral that hit on the issues of insecurity and doubt that had dogged the singer, found dead in a bathtub at age 48, in her later career.

"It's a tree we can all hang from, the inexplicable burden that comes with fame.  Call it doubt, call it fear. I've had mine and I know the famous in the room have had theirs," Costner said at the invitation-only "home going" ceremony that was held for Houston at her childhood church in Newark, N.J.

"The Whitney I knew was still wondering if I'm good enough. Am I pretty enough? Will they like me?" he said. "It was what made her great, and what caused her to stumble at the end."

The Oscar winning actor, now starring in the "Hatfields & McCoys" miniseries on the History Channel, revealed his own anxieties leading up his memorial before the star-studded crowd that included singer Alicia Keys, actor-director Tyler Perry and singer Stevie Wonder, among others.

"Oprah was in the room and Diane Sawyer and all those people I wished were speaking instead of myself," he said today on "GMA."  "What was I going to say?

"You can't be everything to everyone and how people choose to deal with it is something I was speaking to in the room," he said.

Houston was found by her assistant in the bathtub of her hotel room at the Beverly Hills Hotel as she was preparing to attend a pre-Grammy Awards party.  Authorities said her death was complicated by cocaine use and heart disease.

"I saw pretty much what everybody else saw," Costner said of the singer's struggles with addiction. "I was asked a couple of times by closer friends of hers to write her a note.  I did.  I don't know if she ever read them."