Low cholesterol is a very common symptom for people with situations like yours. A theory borrowed from Chronic Fatigue Syn research is this:
The mevalonate pathway has been "shut down" in response to some type of infection, bacterial, parasitic or viral. With this process limited the body cannot produce adequate cholesterol which is the precursor to Pregnenalone (the master hormone). Pregnenalone is the precursor to DHEA, cortisol, estrogen, progesterone, testosterone, and so on. This leads to an imbalance in the HPA axis (hypothalamus-pituitary-adrenal). People with this problem are often diagnosed with chronic fatigue or fibromyalgia.
One theory is the body slows down the mevalonate pathway as defense mechanism against some type of infection.
Do your research before taking DHEA, Pregnenalone, Progesterone or even Melatonin. all can have negative side effects. Our experience has been only positive with Pregnenalone, not so with the other three.