Selma Blair is giving the world a peek into her life with multiple sclerosis. The “Cruel Intentions” and “Lost in Space” actress, 49, took to Instagram Tuesday to share a candid video of her life since being diagnosed with the disease, as a way tomark Multiple Sclerosis Awareness Month. “March is #MSAwareness month,” Blair captioned the post. “May we all find the strength to persevere.” Among the clips in the video — for which she attached Zendaya and Labrinth’s “I’m Tired” track from “Euphoria” — are those of Blair in the hospital, receiving treatments, exhausted in bed, dancing, posing with …