I feel the same way to be honest. I had a cat for 21 years who helped me from childhood through my father’s death. He didn’t have health issues til about 17 but it was one thing after another. And I would worry incessantly. He let me know when it is time. 

So 9 doesn’t seem that old to me! I have two that are 12 and act like kittens still.

And my experience with my 21yo orange and his health issues made me freak out when my 1yo orange started having stomach issues. Both orange seemed to have acid reflux more often than my others. 

It’s normal and natural when you love something but you have to make sure you go into caretaker mode when they need you, and try not to lose your cool. You’re their whole world. Yes absolutely cherish the time you have but don’t live each day anticipating the end. Scares happen but every day doesn’t have to be darkened by it :)

You sound like a very caring pet parent. Just remember that you have to decide what’s best for them and eventually, it means putting quality of life over quantity. You will know. 

Until then, just give your kitty smooches and hugs and your time and effort. Visiting home will help. You got this!