By Keir Mudie Olivia Colman has told how she was so nervous the night she scooped her Oscar that she had to take a beta blocker to calm down. The actress, 50, also revealed she ordered a high neck dress as she suffers from a huge rash when stressed. Colman won her gong in 2019 for The Favourite, the movie in which she played Queen Anne. She tells a new book: “I had been really anti anyone talking about it as I didn’t like the pressure. I had half a beta blocker because I was so nervous. It took away all my fear. I shouldn’t recommend that, but it was great.” The pills slow down the heart. Spea…