A bereaved parent needs all the rest that he or she can possibly have. I know this may not be possible for many families, but the workplace and school need to be sensitive to the needs of a family that has just undergone a major loss. The grief after a week is not the same as after a month. It's a memory whose emotions remain raw to this day. Don't be afraid to cry.
Tears are a release and an essential part of the grief work.
Bear in mind, too, that men and women grieve differently. Women are more open and willing to cry and talk about their pain. Men tend to internalize the sorrow and have different styles of coping. Be easy on yourself. There's no rush and no one should put a timetable to your grief.