The unfortunate truth is exactly what everyone else here wrote, you will continue to get those thoughtless, careless and well meaning but seriously insensitive comments from all directions, Christian and non-Christian alike. Just because you believe that the Lord is walking through the valley with you doesn't mean that the pain isn't there, and that you still need to grieve.
I don't have any other children at home, but I think Steph is right, you love your children, ALL of them and they won't be scarred for life. If anything, they will be better prepared knowing that life isn't always easy, fair and right.
It is difficult to be the one grieving and have to come to a place of understanding and acceptance that others, who do not wear our shoes, will never, ever get it.
I recently read a poem by Annie Johnson Flint that may help to encourage you when faced with situations such as this-
He giveth more grace when the burdens grow greater,
He sendeth more strength when the labors increase;
To added affliction He addeth His mercies,
To multiplied trials His multiplied peace.
When we have exhausted our store of endurance,
When our strength has failed ere the day is half done,
When we reach the end of our hoarded resources
Our Father's full giving is only begun.
His love has no limit, His grace has no measure,
His power no boundary known unto men;
For our of His infinite riches in Jesus
He giveth and giveth and giveth again.