«Look at this process as if it were a feedback loop that you have to break in order to heal. I recommend that you watch Dr. Schubiner's videos, but let me explain a bit how I understand it. Brain sensitization can happen for many reasons: childhood trauma, pressure, stress, self-imposed high standards, etc., accumulated over time. Or simply due to a very prolonged period of stress where you didn't give your nervous system time to recalibrate.
The brain creates symptoms, and these are perpetuated because the person remains in those same states, or due to the fear and worry about the symptoms themselves. Then, this vicious cycle continues and more symptoms can appear. Your brain makes silly associations and views everything as a danger.
For example, at the beginning I was so terrified of what was happening to me because my symptoms would shift, fluctuate, or change, that I had panic attacks. My world became smaller and smaller due to fear. My brain was afraid of many things, for instance, going out into the street or traveling on buses, because I thought the pain would worsen. My brain had even developed a fear of sleeping, since whenever I tried to relax, I experienced hypnic jerks and a constant feeling of anxiety. Currently, I have already overcome those conditioned responses.
Gradually expose yourself to what you stopped doing out of fear, tolerating it to a certain extent. At first, your brain might worsen the symptoms and that is normal, because it has learned that those are dangerous activities; but every time you expose yourself, you will realize they will become less intense until it stops doing it altogether. Remember, the brain learns through repetition.
I'm not going to tell you it's easy at first, because I went through what you're telling me too. Every time I had those hypnic jerks when trying to relax to sleep at night, I stayed calm. Little by little, over time, I felt those sensations getting milder until I don't have them anymore. Literally, my brain learned that it was safe, and that's how it went with many things».