It's going to be hard - perhaps especially for adults - but the worst time is probably Monday evening and Tuesday morning: so remind yourself that if you can get past there it's downhill.ish!
Change morning routine so that you're not hovering around kitchen first thing looking for the kettle, e.g. first shower and dress and then go downstairs for breakfast and water.
.Hide kettle Sunday night
Similarly, move coffee and tea somewhere not close to hand.
.Put bottles and jugs of water in fridge.
Take bottle of water to work, and tell your colleagues why. They may at least support you, even if they don't join in.
Buy more juicy fruits - oranges, plums etc - and put them in fridge or near where kettle normally is.
Have a bar of chocolate at hand for caffeine fix.
If all above fail, ring friendly local priest for spiritual strengthening.