Early in my therapy, when I was (unbeknownst to me) in what might be termed the "infatuation phase" , I had something to grieve about but I guess I couldn't in therapy. T told me that I felt too good when I was around him and so I couldn't feel sad about this thing to grieve it in his presence. So he told me to go home and grieve this outside of his presence. He suggested I write a letter to the object of my grief and try to communicate with him directly (to evoke him). I did this and it was successful. (The letter was not intended to be sent, it was just a tool to allow grief and closure.) So anyway, that was my T's solution. Don't know if it would work for you or not since you don't have such a specific thing you are wanting to grieve.

When I'm in therapy now with T, and I need to be sad, I just do. Sometimes I fight it, but T has tried to teach me to allow the feelings. So Rainbow, maybe you could try to just allow yourself to feel grief, instead of focusing on understanding the exact reasons you need to grieve. I don't think you need to know those in order to grieve. And focusing on trying to know the reasons why will pull you further away from your feelings (intellectualization?).