Selma Blair explains how she felt before MS diagnosis, reveals celebrity pals who supported her

Selma Blair is sharing more details about her struggles with multiple sclerosis, including her emotional reaction to her diagnosis and the friends who have helped along the way.

Blair opened up about her struggles with MS in an interview with Robin Roberts Tuesday on "Good Morning America." It aired just days after she rocked a custom cane during her triumphant return to the red carpet at the Vanity Fair Oscars party.

The disease's impact can be seen and heard in the interview, affecting even the way the actress speaks.

She told Roberts she has spasmodic dysphonia, which causes spasms in the larynx, or voice box, brought on by her primary disease. MS is a progressive neurological disease that attacks the coating of nerve cells, causing sensations of numbness, tingling or burning as well as balance issues, vision problems and other symptoms.

"It is interesting to put it out there, to be here to say, 'This is what my particular case looks like right now,' " Blair, 46, said.

"When I got the diagnosis, I cried with some relief," she said, recalling her first thoughts after learning she had MS in August. "Like, 'Oh, good, I'll be able to do something.' "

Her tears, she realized, "weren't tears of panic. They were tears of knowing that I now had to give in to a body that had loss of control. And there was some relief in that."

"The doctor said, ‘Your life will forever be different,' " Blair recalled in a recent Vanity Fair interview. "And I was like, ‘Well, thank God.’”

Blair said that when her son was born in 2011, she "was in an MS flare-up and didn't know, and I was giving it everything to seem normal."

She recounted, "I was self-medicating when he wasn't with me. I was drinking. I was in pain. I wasn't always drinking, but there were times when I couldn't take it."

An incident nearly three years ago prompted Blair to immediately give up drinking. She was traveling with her son, then 4, from Cancun to Los Angeles and mistook an Ambien pill for an anxiety medication. Some nasty side effects led to Blair blacking out, and she had to be carried off the plane on a stretcher.

“It made me see things differently, and it opened up a conversation with my son about my own past with alcohol," she told Vanity Fair.

Blair's worries were compounded when her pain and symptoms were dismissed when she sought medical answers for her mysterious loss of muscle control and overwhelming fatigue.

"I was really struggling with, 'How am I gonna get by in life?' And [being] not taken seriously by doctors, just, 'Single mother, you're exhausted, financial burden, blah, blah, blah.' "

"I was ashamed and I was doing the best I could and I was a great mother, but it was killing me," she said, adding that she would have to take a nap on the way back from driving her son to school, one mile away.

Frustrated with her inability to get answers about why her body was breaking down, she reached out to fellow actor Michael J. Fox, who has Parkinson's disease, for help.

"I said, 'I don't know who to tell, but I am dropping things. I'm doing strange things,' " Blair said. "He got in touch with me and we began conversations. He really helped me … he gives me hope."

In the Instagram post revealing her diagnosis, Blair thanked actress Elizabeth Berkley for sending her to brother Jason, a neurologist who found lesions on her MRI and identified her symptoms as those of multiple sclerosis.

"I had never been taken seriously until I fell down in front of him trying to sort out what I thought was a pinched nerve," she wrote.

Following her announcement, Blair told Vanity Fair that Amy Schumer reached out, as did Kris Jenner, whom Blair portrayed in "The People v. O.J. Simpson: American Crime Story." Blair joked that Jenner sent her flowers that were "more expensive than my mortgage."

“She really is sharing something so vulnerable, and so scary,” Jenner said. “She showed me what courage is, and how to be brave. I changed a bit of the way I live my life because of her.”

Telling Arthur, her now-7-year-old son from her two-year marriage to designer Jason Bleick, was surprisingly easy. Though Blair always wanted him to "feel safe, never responsible for me," he had already seen her fall and experience other motor-control issues.

"I said, 'I have something called multiple sclerosis.' And he almost cried and said, 'Will it kill you?' And I said, 'No. I mean, we never know what kills us, Arthur. But this is not the doctor telling me I'm dying.' And he was like, 'OK!' "

The actress also discussed her prognosis: "The doctor I saw ... he said within a year I could have – at the time, he said 90 percent of my abilities back."

Even if that turns out not to be true, she said, "If I can still have a conversation, that's good enough. I want to see where I am."

The biggest lesson MS has taught her? "It's fine to feel really crappy and say, 'I gotta,' " Blair said. "And my son gets it and now I've learned not to feel guilty."

She admitted she was initially scared of talking, let alone in public.

But she maintained a positive attitude, joking, "No one has the energy to talk when they're in ... a flare-up. But I do, 'cause I love a camera."