It is indeed a very painful experience. Please do not blame yourself. Life and death is beyond han control. Deaths happen even in the best of hospitals and lives get saved even with bare minimum support. You did what you could. Beyond that it's not in anyone's hands. Please be gentle with yourself and not harsh. At this time of deep grief, you should look after yourself rather than blaming self. Please meet a counsellor if you are unable to to let the guilt go.