I've done some reading on this and it's not, specifically, the thyroid that goes into "survival mode", it's the entire body. In times of extreme stress, the body can shut down all, but the most essential functions.
According to your previous posts, your traumatic experience took place in Feb of this year and it seems that your entire body may have gone into survival mode. Sometimes, certain organs may not resume proper function and this may be the case with your thyroid; however, I think your trauma may have involved more of your bodily functions than just thyroid.
In the case of such a body shut down, the adrenal glands would be greatly stressed, since they produce adrenaline, which is the "fight or flight" hormone. While your thyroid tests indicate hypothyroid, I wonder if your adrenals may be causing the biggest issue. If you haven't had extensive testing done on your adrenals, you probably aren't being treated adequately.
I'm not sure that eHow.com is the best source of information, but if you'd care to post actual links to your information, I'd like to take a look at them.
I understand that you are fighting for your life on both the mental and physical sides. While we can help, to an extent, with the physical side of it, I know that physical issues, sometimes, may not be resolved until the mental ones are; therefore, I strongly urge you to find a doctor experienced in dealing with P.T.S.D., because even if you haven't been formally dx'd with it, that seems to be the prevalent issue.