If My Thyroid Lab Result Is .16 And I Have

If my thyroid lab result is .16 and I have been taking .60 MG Armour Thyroid for the last 5 years, how should the Armour Thyroid be adjusted? My main complaint is slurred speech which started about a year ago, a tremor and shakiness. The only other med I take is Atenolol, plus routine vitamins. Thank you in advance for your time.