BL.,
These kinds of thoughts are common, and are what feed the anxiety and the symptoms...
...so though you say you don't 'feel' anxious, or have reason to be stressed...your thinking says otherwise.
Anxiety is hard wired within our systems. Without it, we would not have a warning system of danger.
However, when those signals become too easily triggered...we become anxious beyond what is necessary for our situation.
So we don't need a reason to be stressed per say. Our systems just get too easily triggered for whatever reason...and the result is an over abundance of our primal warning systems!
So we need to use tools to override this...and one of the way to deal with frigtening thoughts is to counter them with therapy worksheets.
Here is the link that will teach you how to diffuse these fears.
Therapy Work Sheets:
http://www.get.gg/freedownloads2.htm
Hoping this helps!
S.C.