Hi,
No you don't sound cold-hearted at all. My Dad is the same age and I have so many frustrations with him. And, I have the guilt too, since I live thousands of miles away. He asks for my opinion and then literally, laughs in my face and belittles me when I give it to him. For my own sanity, I have had to step back and let him handle his own health problems for the most part.
I think you're on the right path by praying and allowing your HP to help out.