Hi internal
I been reading this post and I see you are making the correct connection between thoughts and feelings.
The symptoms of anxiety, the feelings, like shortness of breath, dizzy, chest pains, tingle in arms/legs etc. and so on are all related to first fear.
When we start adding "what if", what if I have a heart problem? what if I die? what if I pass out? what if I have a blood clot" what if. . . that is second fear.
When we add the second fear to the first we feed the panic monster and create the auto response in our body. It triggers the adrenalin to be release and we go into full "fight or flight" response.
I think you would get alot of info from the book "Hope and Help For Your Nerves" by Claire Weekes. It has been my main source for anxiety/panic and is helping me recover.
We think too much, analyize and the exaggerate the symptoms, all because we fear our own thoughts. Once we can accept that we are creating these symptoms, once we accept that there is nothing wrong with us other than our own thoughts keeping us afraid, then you gain a powerful tool to assist in recovery.