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The nodules in the CT of the lung, are probably lymph nodes, which are normal findings and there is nothing to be worried about them.
Since all your blood tests and bone marrow biopsy have been normal, the elevated blood counts are just incidental findings and are not significant.
It is very unlikely that you can have any major medical disorders inspite of multiple tests and imaging studies like CT showing normal findings. Hence most likely your headache and fatigue are due to functional causes like depression, anxiety or acute stress disorders.
You might consult with your doctor or a psychiatrist. Behavior therapy, stress reduction measures and antianxiety or antidepressent medications might be very helpful to relieve your symptoms.