Suggest Dosage Of Synthroid For A 70 Year Old

Question : I have hypothyroidism that has me chasing it with synthroid . I have changed several time's to different amount's to try to see what work's for me. My Doctor change's my dosage at time's, depending on my Thyroid TSH. Like when my Thyroid was 40 something , he changed it to 200 Synthroid. Then I could not catch it before becoming too low as in TSH. Last time my TSH was 1.98, which is in, but too low in TSH for me. I usually feel best with my TSH being about 6-8. But, getting the correct amount is like trying to catch a greased pig . Now, I have total knowledge of my hypothyroidism , and understand it's cause, being the thyroid out put is too low, because it is not doing it's job, as in thyroid shut down . The last time , my thyroid TSH was in @ 1.89. But my case, the TSH make's me feel better at about 6-7-8 . Which seem's to be my normal Thyroid production , which. Has been stated as too much, but I feel what is best for one , might be a little off for another. In my view, and my doctor's , is what makes me feel best to stick with. I know the Thyroid has more than one function , as in T-3and T4's. It may be more, but this I know. If the thyroid TSH is anywhere around 3-6 for most, is best at 3-6-7-8. Feeling's is the way I got to know my Thyroid. Hypo or hyper is opposit of each other. I went for several uear's before finding cause of my downers. I read about the thyroid , and an older doctor I know was willing to listen, instead of guessing. Between he and I, we have been working at this problem. But, I also take, adderall, and this makes it almost impossible. Adderall , I was taking from other doctor's to up my body's symptom's of being low, every day. Maybe I have answered my own question, but, I think there is more to this than feeling good, about an hour later. Can you see where I am coming from?