You can find involuntarily inner or intereoceptive processes in many aspects of an organism or human being (sleeping, heartbeat, breathing and so on). That is the same for dp topics in solipsism, perception, emotions, moving and more you can imagine. A trigger (trauma, weed...) makes a suddenly interruption in that normally unconscious fixed unit which starting in vulnerable persons the vicious circle of anxiety and perpetuate it so deploy a alienation to your own self, to people or environment because those functions are disturbed due to give not needed attention
The brain is a high economic system (for all nerve cells actions a lot of oxygen and energy etc is needed) so all repetitive mental processes are going on, will quick automated or gets unconsious. That means that your thoughts still working unconscious and you only recognize conscious your metabolism and your (in that case most negativ or emotional numbed) emotions . After automated thoughts it is difficult to make the link to metabolism and emotions.
An abstract or formalized scheme aforementioned developed in cognitive behavious therapy (cbt) is the S-O - R - K- C-scheme and the A-B-C-D-E- scheme:
O (organism included schedule cognition/thoughts - metabolism - emotions)
R (reaction or behaviour, goes back to organism in metaprocessing)
c (consequences, goes back in metaprocessing)
B (believe; organism with cognition/thoughts - metabolism - emotions)
C (consequences or behaviour, goes back to organism in metaprocessing)
D ( inner debate)
E ( effects like conclusions you do, goes back to organism in metaprocessing)
Sure a better and more effective way than the "brooding chair" is to lower the anxious circle of thoughts, worrying or anxiety in the way you begin a so called "angel circle" of positive thinking, which changes your negative belief sooner or later. With the angel circle you can start the possibility of a normal, well being functioning again, because it will be automated as quick as the viscious circle. This works quicker and better when you get the same conviction as you have/had it in the starting of the viscious cycle, which is proven in accompanying strong anxiety/ panic attacks.
Even when you dont feel or not to be convicted in that moment, you should start a angel circle of positive thinking and affirmations in the way you start an inner dialog or even say it loud to you ("i will improve", "i can do positive things meanwile my disorder ", "i have self-efficacy", i can distract, things will change, in doing things i can get pleasure back, my body works well without my attention, i am safety and so on). You find a lot of books of affirmations with countless examples you can use everday, every hour or every minute.Beside that you can hang up your chosen affirmations in papers at the wall in your room.
So the process of automation is a fact, it only works slowly or quicker (depends from your positive belief; unfortunalety you are now in force of strong worrying and anxiety, whereby your positive beliefs at first is less), but it works and your worrying and anxiety will fade out.
Finally an example for the quick process of automation (sure much simpler) :
All which have a driver license, may remember the first hour of learning driving and to shift gears, knows how laborious and how much consciousness is necessary for that. Already after a few repetitions you get caught that you are in a high gear without knowing how you have done it, because it was fast automated respective slipped into the subconscious. And it goes so quick because you had the belief "i can do it" unwritten.