Liz---I know exactly what you are talking about! Have been there, big time. I know what it is like to wake up in the middle of the night and break out in a cold sweat and feel nauseated at the scariness of it all. But, somehow, I always found a way.
What I would always end up doing was babystepping it--and deciding that I wasn't giving up---LOL (as if giving up was even a choice!). The fear was ALWAYS worse than the doing. Taking the first action (baby step) is the hardest part---then action seems to take over and push the fear to the background. It is just amazing how that happens.
If I might suggest---maybe seeing a professional vocational counselor one or two times would get you "jump-started". Just to get the lay of the land, so to speak. Also I might suggest the Red Book--the "Bible" that recruiters use. It is called the Manual of Executive Recruiters. This can lead you to the jobs that are not advertised. The recruiters are listed by industry, location, desired salary, and gives the contact information for each recruiter--Who knew?! (my husband was in human resources for large companies).
Liz--the kind of fear that your talking about is natural (at first)--but, I think it is a sign that the situation is "real" and that you are close to taking steps to making the changes you want/need a reality. I see it as a good sign. One day, you will be looking at all this in your rear view mirror!!!
dandylion