Dear Janey
So sorry to hear about your dad and the problem of trying to work out what is happening when you are not being informed. Having Power of Attorney for Health and Welfare for your father in a time he is confused would have given you the right to get information on his behalf.
Some infections can cause confusion. Is he still on antibiotics of any sort, as I assume he would have been put on them if taken into hospital? He would have to discontinue treatment if there is still any sign of infection.
Who has refused help at home for him? He should and yourself be assessed for support needed before discharge if he is in need of this. You could contact social service: means testing applies.
If he is terminally ill then usually hospice / palliative care would be discussed. So you may need to persist in finding out what is expected in terms of his ongoing care and treatment at home.