I'm not going to a competition while my grandpa is in the hospital
I am sorry to hear that news but why would you stay home from the competition while your grandpa is in he hospital?
It will be stressful for me at the competition while he's in the hospital. Also, I don't want to see the look on his face if I lose.
If you feel like you can't give the competition your full attention because your grandpa is in the hospital, then you would be justified in staying home. But if your grandpa would want you to compete, then you should consider doing it for him.
I think he will understand since I have been running in comps since 6.
It sounds like you have thought this through so I am glad you have made a decision.