Oh dear! I think we have the answer now.
As a person on treatment for Hashis, your TSH should be around 1 and your FT4 should be in the top 25% of the reference range. I think what your doctor is saying is that your results are both within the reference ranges and so are OK, which is really not right at all. They need to be optimal and yours are not. You probably also need vitamin D, vitamin B12 and folate, and iron all checking and optimising as well.
You do not quote the reference ranges (it’s always helpful if you can do this with lab results by the way), but I can already tell that your TSH is way too high and your FT4 is way too low, which will undoubtedly explain the fact that you still have symptoms.
Also, you need to be aware that in a person under 50 with no signs of ischaemic heart disease, the standard starting dose is 100mcg and published, peer reviewed research shows that starting at a lower dose simply prolongs the time it takes for people to be well. From what you say you have never been on a proper starting dose.
After six weeks on 50 and with those results, you should be going up to 75 now anyway. I can’t advise you to do that off your own bat, but if you do, you may feel better and you’d certainly know soon enough if it was too much.
I think now you’ve either got to read up and learn about this condition and re-train your doctor, or look for a doctor who understands that being within the reference range is not enough, someone who will work with you to increase your dose to a realistic level and help you to get to a point where you get your life back.
Also pop into your local branch of Boots and buy the BMA’s book Understanding Thyroid Disorders (or get it from Amazon for Kindle if you have one) That says clearly where your results should be – you could always show that to your doc and ask why there is one rule for everyone else and another rule for you.
Good luck. Keep posting and let us know how you’re getting on.