Hi Lisa,
I am very sorry to hear that your Dad is dealing with pancreatic cancer. It is one of the most devastating cancers there are. It can be a highly frustrating and disheartening time. I lost my beautiful mother earlier this year. She had many similar symptoms. The diagnosis and her passing all happened within a very short period of time.
I agree with Wife that bringing in Hospice at this time, would be a very beneficial thing, for your Dad and family. They can be very helpful in providing whatever your Dad might need in the way of support, ie. pain management, supplies, and provide support, advice and indepth explanations to family as to what will happen in the days to come.
We had my mother outfitted with an inflatable mattress as she was experiencing a lot of bodily discomfort. Limbs, her back. She experienced swelling with fluid as well. The mattress might be something that your Dad may benefit from as well.
As for the minimal eating and drinking, sadly, this is one of the results of this disease and a hard thing to watch and accept. It's a good thing that your Dad is still eating to some extent, but just so you know, this may become next to nothing at some point. I had wanted my mother's doctors to consider feeding my mother intravenously, but they explained that sometimes introducing foods unnaturally, can have consequences such as poor elimination which she was already experiencing. I would suggest just offering whatever foods your Dad might like, and try to see that he has water supply at hand at all times.
I wish you all peace and much strength in the coming days. God bless you.