This is one of the saddest stories I have ever read. I'm sitting here bawling. This is so good! Wow!

After all that, I hate to critize, but you do switch back between past and present tense.

That said just...wow. So, so sad. Oh, you made me want to go and wrap my baby brother up in my arms and never let him go.

Amazing job.

...good stuff here - but could you keep it all in one tense?