We have had wonderful times together the ones I craved when I was younger...circumstances and age brought a closeness and friendship of dreams.
Now he is questioning me like I am not trustworthy.
He’s very angry with me especially regarding family politics that he has no clear memory of any longer .
He also feel nervous about his finances and I am sure to disclose where everything is.
How can I help him and also myself to cope?
Food doesn't taste the same as taste buds also age. Eyesight is a blur, and hearing is muffled. Walking without feeling like you are going to trip is history. Stairs are a major challenge. And all those trips to the bathroom in the middle of the night.
If your Mom had passed, then Dad is also missing the love of his life.
As Plymouth62 had mentioned, find things to make your Dad feel important. My own Dad could fix anything, so I was always asking him for advice. So I would zero in on things I knew he enjoyed talking about.
Give Dad a hobby to do. Like creating a family tree. Drag out the photo albums and ask Dad "who are these people?". Oh how I wished I did that when my folks were still alive. Ancestry.com is fairly easy to use. And newspapers.com is so very interesting using a relative's name to search for articles way back. I found a boot-leg alcohol thief during the American Prohibition in my tree, and she was a female :P
I think sometimes they are trying to adapt to surrendering control and that isn’t easy for most people. Transitioning times are awkward.