how to deal with a really bad day at work

First of all, go ahead: yell. Sometimes, after months (nay, years!) of incompetence, you're allowed to put a colleague in their place. Then open the mysterious bag on your desk, out of which flows two very pretty scarves, knitted by another colleague (now friend). Remind yourself that 99% of the people you work with are good and decent human beings and that 50% of those are also really clever lovely people. Take a deep breath. Boot your computer and prove (in a ridiculously short amount of time) just how incompetent the first colleague is. Bar no holds. Spend the afternoon in your office working to give you that soothing feeling of crossing items off your always-long to do list. Confirm with yourself that your list is as such because people trust you to do certain things. Eat a pear. Spend twenty minutes in the story closet picking books and rhymes and puppets for storytime that evening. Drink a tall glass of water. Play the Pied Piper by saying "storytime starts in TWO minutes!" really loudly in the Children's Department and watch your personal conga line form behind you. Spend thirty-two minutes reading and giggling and singing and dancing and pretending to be a tree and getting hugs from kids as they leave. Realise even fake smiling induces the same chemicals in your brain as real smiling and all of a sudden you feel better. Clean up. Put away the toys. Tuck in the chairs. Put on your coat. Remember that you're still a twenty-something and that old British bitch is going to retire long before you get your first wrinkle.