I Have Had Hypothyroidism For 37 Years And Have Been

I have had hypothyroidism for 37 years and have been able to keep my T4 around 1.6 to 1.7 well within the normal range. However, my TSH has always been below the normal level usually between 0.02 and 0.01. about 12 years ago my doctor at the time tried lowering my medication in hopes of raising my TSH. Instead it only made me feel ill and resulted in the development of Hashimato's nodules on my thyroid. I had my Thyroid removed in 2008, and still have been able to maintain the above levels on my T4 and still by TSH remains extremely low. What could this be an indication of, and is there anything that can be done about the TSH levels? Thank you