Why is my TSH always so low, and how to raise it...

My TSH score was a relatively low .47.

My understanding is that this does not qualify me as hyperthyroid under the new metrics (.3 lower boundary), but would have under the old ones (.5 lower boundary).

This is not that much of a surprise.  I've had doctors tell me my Thyroid was 'borderline' overactive before, but I'm a bit concerned that last time I heard that it was certainly before 2006, which was before the new metrics took effect.  I'm wondering if my thryoid isn't speeding up with age.

I've had a great deal of Anxiety lately, but I wouldn't blame my thyroid for it.  It started six weeks ago, and more likely causes include:

-History of relatively Heavy Weed Smoking (10 years .5g per day, and I have since stopped cold turkey)

-A terrible diet.  I would skip breakfast, fast till a late lunch, then eat poorly once or twice per day with a snack here or there.

-Being borderline Mg deficient (see above)

-A generally poor lifestyle, and horrible sleeping habits (see all of the above).

I had 'all-over-twitching' which was very light and random (along with some other symptoms of an Anxiety Disorder), and I went to see a GP and a Neurologist about it, who both told me I had a case of the ole' "Just Anxieties".  My neuro pointed out that I was borderline Mg deficient at the time of my bloodwork, and that was after I had taken Mg supplements for a few days.

These symptoms are not uncommon among anxiety sufferers.  See this wikipedia page which stops just short of assigning causation to Anxiety in the syndrome known as Benign Fasciculation.  
http://en.wikipedia.org/wiki/Benign_fasciculation_syndrome

That describes my symptoms to a 'T', though mine were mild compared to what is shown there.

So I went to see a Psychiatrist who gave me some meds to address the anxiety and probable underlying depression.  

After seeing the neurologist and getting a clean bill of health my anxiety has been much better.  The Seroquel I take may have helped, too.  I also was taking Xanax regularly, but now I take it only as needed.

The twitching and all the symptoms, while not completely gone, are much better.  Where I used to get several random fasciculations per minute, mostly in my legs, I know get a handful per day.  They've always been brief and fleeting.  Were it not for the latent Anxiety, I may not even notice.  For all I know this is baseline for me.

Anyway, I'm a bit concerned that despite the hunger I get from the Seroquel I'm having trouble putting the weight anxiety took back on.  I can't really spare it.  

This is the story of my life, really.  I'm 5'11" 140 now, and even when I hit the gym for months on end (haven't in a year) while taking weight gainer and creatine, I will get quite 'buff', but I've never broken 155lbs.

I know that a fast thyroid isn't good for anxiety.  It's certainly not good for mine, because as you've probably surmised I have Health Anxiety (not quite Hypochondria).

I have a background in Behavioral Sciences, and I've been studying again lately, so I have no doubt that I have an Anxiety Disorder which is on its way to remission, and not Graves Disease.  I did lose weight, but I had no appetite at the time either.  I wasn't intolerant to heat, I didn't experience hair loss, I did lose some libido, but no diarrhea, nausea, or vomiting.  I wasn't hyperactive.

I did experience depression, anxiety, and irritability but all my possible symptoms of hyperthyroidism overlap with symptoms of my mental health condition, and as I've stated, they are better now.

My questions are as follows:

Is it possible that my lifestyle or mental health caused my thyroid to be more active than usual, rather than the other way around?

I got some bugleweed and motherwort, to supplement.  Both are anecdotally known to help with anxiety, and there is evidence they work for hyperthyroidism as well.  Is there anything else I can do to 'slow down' my thyroid, aside from taking medication?  

My psychiatrist said he would give me T4 if I wanted it, but I want to explore my options before I do that.

Is there any general advice you guys can give me?

[AR-10]

You do not want to take a T4 med if you are borderline hyperthyroid. That would make it worse.

If you want a true picture of what your thyroid hormone levels are, you need to ask for a Free T4 test and a Free T3 test. An antibody test called a TSI test would confirm or rule out Grave's Disease.

The whole thing may be lifestyle related and sort itself out.