As usual succinctly and helpfully expressed, though you'd never get a pass grade on a counselling course with such directiveness!

The story of Queen Victoria's obsessive mourning after the death of Albert should be a cautionary tale for us all; rather than moving on and being the best Queen / Mother / Grandmother that she could be, she choose to cling on to the memory of late husband to the detriment of all those close to her. In the same way you are surely depriving others of your gifts and friendship by for ever looking back. I'd encourage you to look for opportunities to get involved with voluntary activities from on as wide a scale as possible, in the expectation that something somewhere is likely to click and joyful memories of the past start to fall into a healthy perspective rather than being an overwhelming distraction from living in the present.