Are Lymphocytes, including WBC's and CD4's usually higher in the afternoon than morning? If so, are RBC's, Hemaglobin and Hematocrit usually higher too in the afternoon and evening? Would that explain why my energy is sapped in the morning and I pick up a bit in the afternoon?
Are there average increases/decreases for the above, depending on time of day?
Yes, there are variations in blood cell counts, hormone levels, and other parameters within the body throughout the day-night cycle. However, diurnal changes in red blood cells, hemoglobin, or hematocrit are minimal and certainly not significant enough to affect your energy levels.
Anemia, on the other hand, can indeed be associated with fatigue. If you are anemic (hgb less than 12 g/dL for women, 14 g/dl for men), you need to find out why. Once the cause is determined, specific treatment can be taken to remedy the problem.