It sounds like you are grieving this very significant loss. When we lose someone close, the "closure" occurs gradually, over a long period of time, as the memories gradually become less painful. We don't just forget about the person we have lost.

If you have lost someone to death, if you have lost a close friendship, if you have lost another lover--think about what helped you grieve, and try those same concepts here.

I'm so sorry for this very significant loss.