My cousin's daughter was born with a severe heart defect and she wasn't supposed to live to her first birthday. She was a fighter and managed to live to her 8th birthday. Of course, her death devasted my cousin and his wife - it devasted all of us.
I believe that children who leave us before the 'natural order' of life (die before their parents) are here to teach us something. Perhaps I'm just seeking patterns or searching for some kind of meaning, but what I learned from this is that life is fragile, love is powerful, and life fights to live.
In her short time on earth, she was part of this existence as we know it and part of a loving family. Love is life and life is meaningful with love.
Keep fighting Alex. You are loved.