This will get easier over the next couple of days so bear with it. The inflammatory response is around 3 days, so this is why your intake went down after the first day as the swelling kicks in. Try sucking some ice, ice lollies – can help with internal swelling and also aids hydration. Keep sipping continuously as you are right you really needs to be trying to increase the overall intake.
Hopefully things start to improve from tomorrow, maybe try some liquid paracetamol to see if this helps xx