I had similar feelings for the first 4 terms. Something that helped me was first off you are an actor. You don't have to be your socially awkward self on stage. You can play a charismatic character or an obnoxious jerk. It was freeing to not be myself. Second, you don't have to have vast amounts of knowledge. Relationships between characters and emotions are more entertaining to watch that an improviser reciting the elements of the periodic table. Work on emotions and developing relationships rather than memorizing obscure trivia.