Matthew, this is one of most heartbreaking but beautiful stories I've ever read. Perhaps your oak tree didn't grow but this story did. And, maybe, it will help someone else.
I am so, so sorry. There are no words to comfort you so I won't try. People who say "all things happen for a reason" and "time heals all wounds" are wrong and callous.
I could not be more pleased that you choice to share such a human story with us. I hope you grow other babies and other oak trees.