Chronic obstructive pulmonary disease (COPD) ordinarily does not cause
chest pain, unless there is rib or nerve damage due to hard coughing. Also the
pain would not be a sign of lung cancer, when the CT was normal.
The pain could be due to a pinched nerve, either along the ribs or in the spine. You should have evaluation for a pinched nerve in the spine, often referred to as nerve root compression. It is unfair to suggest that you are "imagining" the pain.