Wow, nearly EXACTLY my symptoms. Numb face, tightness, tinnitus.

Also, doctors stumped, and also out of nowhere - I was running 3-4 miles a day 3x a week, lifting weights the other days, eating organic food and tons of fruits and vegetables.

1. See a biological dentist, period. Do not waste time with anyone else.
2. Get your amalgams out. Just do it. But do it right.
3. Read every single thing you can, and try to find the most rational system you can. Bex is a very good resource here for finding real info, not someone trying to sell you something. Go to the chelation groups on yahoo and read the threads.
4. You need to have some courage. It's scary to leave the world of doctors and go off on your own, but at some point you need to. This may not be mercury (as it might not be mercury in my case). But it may well be. NOTHING else explains my symptoms, and I've stumped neurologists, psychologists, primary care docs. I finally found a doc who believes in heavy metal poisoning (though he may be a bit of a huckster himself. But anyway...).

Good luck. This stuff is scary. But actually, if you do the amalgams right, find a supplement mix that works for you, and then consider chelating, it's actually not that bad. It's doable.