An excessive stress response and inability for the adrenaline system to stop characterizes my problems. I feel as though my condition is a hybrid of CFS and PTSD (Post-Traumatic Stress Disorder). On one hand, I am more functional, particularly recently, than many others with CFS in that I can leave my house and am able to be physical if I am cautious about my activity -- and sometimes if I'm not as well. I can go on hikes and not get PEM. Yet at other times, I will feel a PEM burn for weeks through my body, especially legs and arms, from less activity.
Meanwhile, what is much more present is pain and tension in the region around the base of my brain and often extending into my chest. When I'm agitated with stress it gets extreme, and if I have a genuinely stressful situation or conflict it can become debilitating. Mild shocks feel extreme. Even something minor, like an error typing, which in most people is not a noticeable source of stress, causes a shot of adrenaline in me. A bump in the road while in a car sends a blast of adrenaline through me, like a bomb went off. I can't decide whether it is the gas being put on (sympathetic nervous system is too strong) or that the brakes don't work (parasympathetic system is too weak).
It does seem as though the excesses of the nervous system are what leaves me weak. I somewhat alternate between wired and tired, as though the wired periods drain the body, and then a period of exhaustion follows, until there is enough adrenaline/other factors to create the wired/tense feeling again, in a relentless cycle.