What should I do about thyroid cancer?

My father's health deteriorated so rapidly that
after a health checkup, we rushed to a university hospital
to schedule surgery for a thyroid nodule.
They skipped the biopsy because they said it would have to be
removed anyway, so they suggested performing the surgery first and then doing the biopsy.
However, right before the surgery, his physical condition became so poor
that he couldn't undergo the procedure on the scheduled day.
For about a week, they conducted various tests and administered nutritional supplements
to stabilize his condition to some extent.
His sodium levels were in the low 100s, which was dangerous,
but fortunately, the levels rose, and he finally went in for surgery.
I had never lived with much interest in thyroid cancer,
and I naturally assumed it would be one of the common types that account for 95% of cases.
While he was in the hospital, we did many preliminary tests,
and since they said surgery was possible, I waited only thinking about how to help him recover after surgery.
I even picked out ice cream for him to eat after his fast...
But just one hour after he went into surgery, the attending physician told us
that they couldn't perform the surgery in this state; it was too serious.
They said if they proceeded forcefully, he might pass away during the operation...
I can't even remember clearly what was said.
I just wailed.
I never imagined my father would fall into that 1% category of cancer...
They said if the biopsy results show anaplastic carcinoma, there is no point in surgery,
and it is pure despair.
The invasion into the esophagus, trachea, and bronchi has progressed quite far,
and they said they have to break the collarbone to remove everything down to the lower part...
Even then, if it is anaplastic, surgery is meaningless, and it would just be a matter of "trying anything at all."
Because of the upcoming holidays, it looks like we will have to wait about two weeks
just for the biopsy results, and I feel like I'm going crazy just waiting around with my hands tied.
I keep thinking that it would have been better if we had done the biopsy first,
but ultimately, I feel it is mostly my fault for not knowing anything until it came to this.
Searching for information only makes me feel more hopeless.
I have no idea what to do, and I feel so suffocated that I am just posting this.
Could I perhaps get any information if anyone knows anything?
My father heard the explanation, but because the professor spoke so gently,
he only thinks that they couldn't remove everything because the nodule was too large.
Waiting for the biopsy results, undergoing more tests, preparing for surgery...
Is it okay to just wait like this?
I heard anaplastic carcinoma is an emergency and that Gangnam Severance Hospital is famous for it;
could we go there as an emergency case?
I really don't know what to do first.
They told us to come to the outpatient clinic after discharge, but I asked them to extend his hospitalization.
Going home offers no answers, but since it's a holiday, the hospital said
there are only a few doctors on duty and there isn't much they can do, but I'm still worried about what to do if it becomes a critical emergency.
Recently, my mother also had a bad prognosis from a car accident and was assessed for permanent disability,
and with my father being hit all at once, I know I shouldn't feel this way, but I just want to die.