Good choice! Great job on resisting 'Dr. Google' :)
Yes, this is a confusing and disturbing experience...to feel calm, yet have physical symptoms.
It leads us to negative, scary thought patterns...such as
'There must be something wrong with my body, since I am feeling this way...and there is no real reason for it.'
However, it is common to have symptoms and even attacks when we are not 'feeling' anxious.
I think that one of the reasons is that we get so good at compartmentalizing stress, that it just comes out where and when it can.
Another factor is that we don't always realize what stress feels like after awhile...as we have become accustomed to it, and are good at adapting. Our subconscious registers it however, and lets us know!
Use your coping skills. Have you tried the Progressive Muscle Relaxation? Here is the link.:)
http://www.stress-relief-exercises.com/progressive_muscle_relaxation.html
Another tool I like to use is this positive mantra:
'I am okay, this is just anxiety making me feel this way.'
Give these techniques a try, and hopefully you will get some relief. Let us know how you are doing soon...and keep posting (as much as you need or want to!)
S.C.