Oh, Lord! How dreadful for you all. I hope they recover quickly and well.
As for you feeling bad about the diet, frankly, who gives a flying stuff?! There are way more important things in life than a little blip!
I've experienced that sort of shock and there's absolutely no way to prepare for it, or to carry on as normal... You did exactly what you and your body needed to, in that moment, and quite right too. Don't give it another thought. Look after yourself and those around you however you need.
I hope everything goes as well as it possibly can,
Hugs,
Marianne x