Jealousy

I noticed in early grief a feeling of jealousy. I had a hard time dealing with this in early grief. The idea of why did my daughter have to die and someone else's get to live. This sounds terrible as I would never wish the pain of losing a child on anyone, but I cannot deny that it was difficult seeing friends and family doing things with their children while suffering the pain of losing my own. Has anyone else felt this way, or am I the only one?