How do I handle visiting my dad watching the life go out of him?

My Dad is sick with kidney disease. And I know he we'll pass away with out a transplant.
I tried visiting him but it just gets too depressing to literally watch the life go out of him.
I tried watching him get dialysis. But that proved too much for me.
There is so little I am comfortable doing anymore.
And it's so morbid I keep expecting him to die . So he we'll feel no more pain. And I can move on with my life.