Will allegra (fexofenadine) or zyrtec help treat fatique, mood disturbances, and facial tingling associated with histamine and cytokine release? Or is it only effective at treating the symptoms listed on the box?

Antihistamines. If the symptoms that you describe are coming from allergic rhinitis, then there is a likelihood that some of them will be helped with those medications. Remember that zyrtec may cause drowsiness a little more than some other meds except for benadryl (diphenhydramine).
It may. Better to see your dermatologist for evaluation and to discuss treatment options.