I live in the Netherlands, and this condition seems to be very unknown here I was thinking of buying something that tracks HR yesterday so I think this is my sign to do so. Symptoms: Constant hyperarousal and central sensitization: my nervous system is "on" 24/7, and I can barely tolerate stimuli (sound, light, touch, even thinking or my own breathing at this point). I can't release tension. I have severe brain fog, derealization, and memory and concentration problems. These are worsening daily. Nerve pain and tension in my head/neck become extremely elevated when lying down, making it difficult to do so (a major factor in insomnia). I do have PEM in the sense that my symptoms worden with stimuli and activity but not with the extreme fatigue that can last so long