I was watching a youtube clip of a Monk, can't remember his name Yattumundo or something? An American Thai forest monk. He mentioned that it was wrong to grieve when a loved one dies. Now I hate to take issue with a monk, but surely grieving is natural and that if you force yourself not to grieve you'll only suppress it and it'll be even more unhealthy.
I think to be able to grieve the death of a parent or child is necessary.
"The original heart/mind shines like pure, clear water with the sweetest taste. But if the heart is pure, is our practice over? No, we must not cling even to this purity. We must go beyond all duality, all concepts, all bad, all good, all pure, all impure. We must go beyond self and nonself, beyond birth and death. When we see with the eye of wisdom, we know that the true Buddha is timeless, unborn, unrelated to any body, any history, any image. Buddha is the ground of all being, the realization of the truth of the unmoving mind.” Ajahn Chah