I had stopped drinking Diet
Coke and coffee and had started taking copper, magnesium, calcium, and selenium per ithyroid.com. It's hard to say which if any element caused the end of the problem at the time. Now, however, my heart rate is back up (though not as high at all), I'm gaining weight, and feeling very relaxed. My GP ran more tests that I fully expected would show that I was in a state of hypothyroid instead of hyperthyroid. I was wrong. My TSH is now 0.019, Free T4 is 2.