I am sceptical of the blood work done. During those periods of fatigue, there will be a noticable fluctuation in numerous chemical factors in circulating blood.
Certain parasites can secrete hormone-like chemicals which will directly act upon leptin receptors ect. I would guess that your 'd' and 'ht' receptors are involved. These affect metabolic processes such as appetite, sleep, and energy.
There may be increases in immunoglobulins which should have been throughly examined in blood work. Shroom