Oh Maya, you have my warm thoughts for healing for your father, and for courage and hope to stay constant in your own heart. I know of this condition, for my own mother was diagnosed about 6 weeks ago by her gerontologist. Luckily, after 4 weeks of Prednisone, she was completely restored to her former health and the doctor discontinued her medication for the condition.
It is a very tough situation...not knowing whether your loved one will get better or decline. I want to wish him a speedy recovery and am compelled to say, what a gift he has, with such a wonderful daughter as you!