It is very difficult to do experimentation on oneself when the measures are anxiety and sex drive.
Just the realization that one is in an experiment and has expectations of the outcome causes stress which can increase norepinephrine levels which can then increase anxiety and reduce sex drive - irrespective of whether or not Vitamin C is there. This is why when subjects are in experiments, a double-blind placebo controlled study is often best - where the subject doesn't know what they are taking and the experimenter doesn't know what they are giving. The placebo effect can be extremely potent as is the knowledge of being in an experiment. Just the increase in thinking about the subject and self-observation - increases stress and anxiety.
Taking tryptophan - which has sedative properties - may have reduced one's anxiety during such an experiment - thus undoing the increase in anxiety of the experiment itself. But then, this introduces another variable into the experiment that complicates interpretation.
As a physician, I see large numbers of patients and can thus see patterns in response that one may not see in an individual. This gives me a much more powerful vantage point to observe responses to medications or other interventions to gain an understanding of the processes involved, than one has if one experiments on oneself.
Norepinephrine is not always raised in adrenal fatigue. The other neurotransmitters - serotonin, GABA, dopamine - may be reduced instead, thus causing a relative increase in norepinephrine, not an absolute increase in norepinephrine. This also has to be correlated with brain function. Glutamate may be increased rather than norepinephrine, etc.
Many times, adrenal fatigue does not exist without other comorbid conditions such as hypogonadism or hypothyroidism or nutritional deficiencies. This complicates the picture greatly, making it more difficult to do an adrenal treatment in isolation since the other comorbid conditions may link together with adrenal fatigue and may have to be addressed simultaneously.
When taking a single nutrient - such as Vitamin C - one may be assuming that one's nutrition of other nutrients is optimal. This may not be the case. Thus deficiencies in other nutrients may be exposed when Vitamin C is taken, particularly at large doses.
When Vitamin C is taken alone, it can reduce copper, manganese, and zinc absorption - resulting in a deficiency of these if one's levels were low to begin with - resulting in unwanted effects. Zinc deficiency, for example, can cause reduced sex drive or libido.
A copper deficiency may then impair activity of dopamine-beta-hydroxylase - impairing conversion of dopamine to norepinephrine - undoing Vitamin C's effects on dopamine-beta-hydroxylase.
Vitamin C as an antioxidant helps adrenal function. It is concentrated in the adrenal glands and brain is up to 20 times more than the rest of the body.
In the brain, Vitamin C can reduce NMDA glutamate receptor responsiveness to glutamate, which may then help increase dopamine activity, which may then reduce norepinephrine activity, etc.
Thus the story is complex and may depend on the individual's situation - the interactions among the neurotransmitters, hormone, cytokines, nutrients, medications, stresses, health status, etc. Which direction a person may go depends on the balance of the metabolic pathways activated by an intervention. Some pathways (e.g. Vitamin C's effect on dopamine and norepinephrine or
Testosterone's effect on thyroid hormone) can go both ways (up or down).
One has to make some hypothesis and change treatment if unwanted effects occur. But it can be made much more difficult by very complex interactions among the neurotransmitters, hormones, cytokines, and nutrients.
And that's partially the rest of the story.