The best possible thing to do is eat a great, restorative meal.
Walk across the Liffey while it's light and after the sun has set.
Collapse like a sack of laundry on your bed, in your clothes, and sleep till midnight, when you will wake, brush your teeth, and collapse again like another sack of laundry, or the same, but not in your clothes, and with clean teeth. Sleep till the early, early hours of morning.
Wake up and write. You're in Dublin.