I will go to my grandmother’s house this afternoon~

My grandmother is very good to me. She always cooked delicious meals for me when I was young！And she always saved her best for me. She is taking care of me, and I love her very much. (She took care of me or she was always taking care of me (If she doesn't take care of you now.  Either or could work in this situation.) or She takes care of me. (If to some degree she still takes care of you.))

Now，my grandmother is older, and she broke her a leg. I'm very distressed for her. I‘m not that little boy, my grandmother caring for me from I’m a little boy to a large one (You may not even need "a large one" in this sentence.  Also, I think this sentence you wrote is quite beautiful.). I will care for her same as before she cared me.