Hi cloudy and welcome.
Wow, that sounds very frightening! Many people have nightmares...I think almost everyone at some point has. People with anxiety can certainly have their share...but having nightmares is not necessarily indicative of anxiety. Unless you are having other anxiety issues and symptoms, then you can probably just assume that like everyone, you are having a particularly recurrent bad dream.
One thing that did raise some red flags for me in your post however, was the feeling of being held down by a force. This almost sounds like it could be sleep paralysis...a form of sleep disorder that reoccurs, and has some of the same characteristics that you described.
You may want to look it up or discuss it with your doctor. I will put a link here as well.:)
http://en.wikipedia.org/wiki/Sleep_paralysis
Post with us anytime if you think that you are also experiencing anxiety that we could help you with through support here.
Take care,
Scaredy Cat