As i said, all is relatively simple yet very complicated as it is biochemistry :) All the **** that is happening = Prolonged stress = increased cortisol levels = physical fatigue and cause of depression. C simply suppresses secretion of cortisol. 

It's a shame that medical community is so focused on stuffing people with much stronger medical substances too early where in early and mild cases this would be a perfectly viable solution. I guess it's business since C is way too cheap.