Sudden death

My 2 year old dog suddenly died today.

I feel like I failed him as an owner. I keep thinking of what I could've done to keep him alive today... but he is gone forever....

The day before it happened, my parents told me that he ate cooked bone and that he was vomiting. I thought we should keep him monitored for now and see if he gets better... I didn't know that the next day he'll leave us....

My parents rushed him to the hospital because he was pooping blood and then he died in the vet when they left. He was supposed to have a surgery for the next days but they said he was too weak to have one and is already vomiting blood. (I was at work when all of these was happening!!!!) I couldn't believe myself that I let my dog die!!

I hate myself that I let him suffer to death. I wasn't able to see and hold him for his last breath.

It is my first time grieving for a pet... I don't know how to deal with this... Everytime I see his pictures and videos, I can't believe I'll never see him again....