I totally understand about the feeling of "bereavement," lovemabub. To my knowledge, people often go through the same stages of grief when they lose or feel they've lost a relationship as when they've actually lost a person to death. It seems to me you know it's not death, that's why you said "living bereavement." But, no doubt, one can still sense a void.
IMO, posters here having given you very good ideas. And I'm glad you've decided to rethink your attitude and are making plans to alleviate the problem. Best to you, moving forward!