I went to work and spent my entire shift not really talking much to my fellow colleagues because I didn't want them to talk to me when I wasn't in the mood to talk. Obviously I couldn't stay silent all the time as I had to engage with customers if they asked me questions. The reason for my low mood was because I had little time to eat at lunch time before my shift started and so had to wait for 4 hours until my shift ended. I feel better now that I've eaten and had a cup of coffee.