So sorry for your bought with dental pain and infection. Do you have a regular doctor or Nurse Practitioner? As a nurse myself, and a former dental pain suffered for so long I can't remember. (The pain stopped when I got dentures, fyi). But, your optic and other nerves run through small...
a whole cup of milk in your icing will likely make the icing very thin. My buttercream Icing recipe calls for 1 - 2 tbsp. ofmilk oheavy cream. Good luck!