Selma Blair says she felt "relief" after being diagnosed with multiple sclerosis in 2018. The 46-year-old actress discussed her experience with the disease, which affects the central nervous system, in an interview during Tuesday's episode of "Good Morning America." Blair told host Robin Roberts she was in the midst of a flare-up and experiencing spasmodic dysphonia, a neurological disorder affecting the voice. "I am doing very well," she said. "I am very happy to see you. Being able to just put out what being in the middle of an aggressive form of multiple sclerosis is like." The "Cruel Intentions" star recalled her emotional reaction to being diagnosed with MS in August. "I cried," she said. "I had tears. They 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." Blair said she experienced years of pain and other symptoms prior to her diagnosis but was "not taken seriously by doctors." "Ever since my son was born I was in an MS flare-up and didn't know, and I was giving it everything to seem normal," she said. "I was ashamed and I was doing the best I could ... so when I got the diagnosis, I cried with some relief." Blair has been in touch with actor Michael J. Fox, who is diagnosed with Parkinson's disease, and said the actor gives her hope. She said her doctor is optimistic about her prognosis, although she's not taking her health for granted. "The doctor I saw, he said within a year I could have -- at the time he said -- 90 percent of my abilities back. So this is to say, let's meet again next year and see if I'm better," the star said. Blair went public about her MS diagnosis in August. She returned to the red carpet Sunday at the Oscars ceremony in Los Angeles.