What could I have done?

What could I have done differently?  If I was with him that morning, would it have happened?  If I hadn't gone for a bike ride and played with him a little longer, would he still be here?  Was it the greek yogurt and bananas I gave him for breakfast?  When he stopped breathing, he threw up bananas...could it have been them?  Maybe it was because he had started drinking formula?  It had only been a few weeks since I had introduced it and he was still getting breast milk, but could that have been the reason?  Perhaps I should have never sent him to daycare, but I didn't like the idea of him being home all day with a nanny.  I wanted him to be with other kids and he loved it there.  Still, I should have been with him.  Was he not getting enough vitamin C, Iron, what?  I worried about these things constantly, what did I miss?  Was it the vaccinations?  He had a Hepatitis B shot the week before.  I am not sure why an infant needs a Hepatitis B shot anyway.  Was there an abnormality that happened in his brain because of my prenatal care?  I trust my doctor and he told me throughout how great Max was doing.  I know I should have changed my pediatrician.  He was cold and socially inept and very traditional, but he diagnosed Max's jaundice so quick, I thought he was the right choice.  What could I have done differently so that Max would still be here with me?  Did I not police his daycare sleep environment well enough?  All of the other kids there are still alive.  Was his mattress here or there giving off fumes?  Should he have been wearing a monitor at all times?  He was perfectly healthy the morning of July 19th.  There was no indicator that this would happen.  I loved him as much as anyone loves their child.  I was madly in love with him (still am).  If there was nothing that I could have done, how will I make sure this never happens again?  How can I give you advice about how to make sure it doesn't happen to you?  I think about this all day long.  It intermingles with thoughts about where he is now. Does he know how much I love and miss him?  Why my baby?  I can't live without him!  He was so cute.  I loved the way he was in my arms, in his bumbo chair, when he slept, when he was in the bathtub, when he nursed, when he ate, when we danced, when I read to him, when I rubbed his back, when I sang to him.  I think about him all day long and what I could have done differently so that I could still admire all of those things I love about him.