I'm right here with you. My 4.5 year old also has a temperature today, sickly, painfully whining and grizzly.
My 2.5 year old is getting stir crazy... I couldn't take him to nursery because the other is too ill to be moved.
I live in a village, I don't drive, I have ebay items to post urgently (if they're late, buyers don't care if your children were so ill you were housebound, they Neg you anyway then you can't sell because of the Negs then you have no money to buy things for your children ...), I have no milk in the house, no food, ..
Times like this, I wish so much I had their father with me to just 'be there' let alone run urgent errands.
But then I remember, if he was, he would only be sat on the computer telling me what a useless C* I am that I can't multitask when the kids are ill and it's my own fault anyway for not getting her jabbed/moving to a village where illness goes in circles/giving her school meals not packed lunches/ who knows what else obscure.
And most two parent families, the other parent is out at work all day anyway whilst you are tending your ill child.
So I think to myself, if I can get my ill child through this, I can do anything for her.
She's dozing now, she will get through it, young children are troupers, her immune system is working in overdrive to make it all better. It passes. The emotional toll it takes out of you is surprising though, isn't it?