Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture the tweeter's mental state.
Tweet: Been up since 4am. Too scared to go back to sleep #nightmare — feeling scared
This tweet contains emotions: 
fear, pessimism, sadness