I?ve got the same issue with panic and its relation with thought. I fall into an extreme panic whenever a situation presents itself which requires any planning or sustained cognitive effort. The panic leaves me feeling fuzzy, foggy and unable to gather my thoughts in order to complete the task, and also adds an initial fear of attempting the exercise again. The panic can set in during project planning at work, making a budget, or even sitting down to watch a movie or read a book.
My suspicion is that our ruminations have a higher priority than anything else we feel we should be taking part in at the moment. Humans have a system of interrupts much like a modern computer. An input to the system will throw an interrupt which will then cause a pre-programmed function to execute. An interrupt with a higher level than what is already being processed will cause the current process to be set aside and the higher interrupt dealt with immediately.
Using this analogy it becomes easier to understand why sufferers of DP and anxiety have so many problems with memory, concentration, and also the fear that comes with knowing that they must remain focused for a period of time, making a conscious effort not to handle any of these higher interrupts until their task is done. No matter whether the rumination is 'thinking about thinking', worrying that you may have a heart condition, or freaking out about your supposed inability to remember what you ate for breakfast, the result is still the same. You?ve just been broken away from whatever you were doing and then frustration, fear and a feeling of helplessness of ever returning to 'normal' soon follows.
Also, indulging in any activity other than attempting to find an answer about why we might be 'like this' may be seen as an unnecessary diversion from the riddle that needs to be solved before we allow ourselves to start ?living? again.
I?m guessing that some of us, most definitely myself, may have put the cart before the horse in this instance. The ruminations and panic will only cease once we place our anxieties and ruminations at a lower priority than all of our daily tasks, and start 'living' again.