Yep, every body does. I like the exercise suggestion already given and the thought processes thing.
The best book I've read so far on the subject of stress reactions, where they come from, what can unwittingly contribute to them and what you can do about them is this one: http://www.amazon.com/Anxiety-Phobia-Workbook-Fourth/dp/1572244135 It's written with some serious cases in mind, but applying it's insights can fortify anyone desiring to take responsibility for managing their stress responses.
Another thing that might help your inner ear canal and muscles in your head to relax is ear candling. It's not a wax remover as some people erroneously believe, so beware of buying into that bunk, but the warmth generated by the process is awesome for relaxing muscles that need a reminder of what it's like to actually relax. :)
Specific to your mention of jaw clenching/teeth grinding, I've heard dentists can help with that sort of thing as well, so it may serve you to ask yours about it. Keep in mind that a real fix to the underlying issue is superior to a bandaid fix to just one symptom. You seem on the right track with managing anxiety/stress/fear as a whole by means of things like exercise and any other techniques you can find that you are willing to do.
You're inherently worth the effort and the benefits of calm are totally worthwhile! :)