An underactive thyroid will also cause hair loss. It is worth looking into and quite straightforward to treat. If you have mercury toxicity you almost certainly have thyroid issues. Get the doctor to test for Free T4 and T3 levels - the TSH test is meaningless - and you may consider a combination T3 / T4 treatment. Have a look at these links.

http://www.stopthethyroidmadness.com/long-and-pathetic/

http://www.mercola.com/article/hypothyroid/diagnosis.htm