I love my granddad but not as he is now
Why don't you love him as he is now?
I am sad that he is so old now.
You can still love your grandparent as they start to decline in their old age. His ageing should not change your love for your him.
It hurts to see my granddad in this state.
It's not uncommon to feel sad when you see someone start to age, but you should still love him. I'm sure seeing you would really mean a lot to him.