Unclear, as others are. So you are already in college? You shouldn’t say anything about high school grades. I’m sorry for your loss and hospitalization. However, this information isn’t going to be of much concern to a college, except in a negative way, sorry to say.
It seems that your grandmother’s health issues occurred in college, in which case perhaps an advisor at your current college could add this info as an additional statement. I feel it’s reasonable to mention that you were your grandma’s caregiver, but not your own struggle. It is not a selling point.