Cats always look a bit "mysterious". I have had many cats, and I now have a 3 month old kitten. And,as all cats, he will often sit stock still and stare at me; as if he is saying "I don't obey you! You obey me!". And cats eyes often change colour!
Sorry to hear of your illness. I am very seriously ill myself.But I am old.(82).
So, as I do, keep telling yourself, "Yes,I am ill.But I'm not dead yet!"