You have fallen victim to the two main obstacles to getting diagnosed and treated effectively for hypothyroidism. First is the "Immaculate TSH Belief" by which some doctors only want to use TSH to diagnose and medicate a hypo patient. this absolutely does not work, because TSH is a pituitary hormone that is affected by so many variables that at best it is an indicator, to be considered along with more important indicators such as symptoms, and also levels of the biologically active thyroid hormones, Free T3 and Free T4. Of these, Free T3 is the most important because it largely regulates metabolism and many other body functions. Scientific studies have also shown that Free T3 correlated best with hypo symptoms, while Free T4 and TSH did not correlate.
It is good that you have at least been tested for FT3 an FT4. Unfortunately the next obstacle you faced was the use of "Reference Range Endocrinology", by which most doctors will tell you that a thyroid test result that falls anywhere within the reference range is adequate for you. This is also wrong. The ranges are far too broad. Many members, myself included, report that symptom relief for them required that Free T3 was adjusted into the upper third of its range and Free T4 adjusted to around the middle of its range. Your FT4 is fine as is. Your hypo symptoms are due to your Free T3 being too low in the range.
From your FT4 and FT3 levels, it is clear that you are not adequately converting the T4 med to enough T3. In order to raise your FT3 level, you need a change in meds to add in a source of T3. You could substitute a T4/ T3 combo med like Armour Thyroid or Nature-Throid, or you could try adding a small amount of Cytomel to your Levo dosage. You should also be aware that since you appear to have Hashimoto's Thyroiditis, your meds will need to be occasionally adjusted upward to offset the loss of natural thyroid hormone production, as the Hashi's antibodies gradually destroy your thyroid glands.
A good thyroid doctor will treat a hypo patient clinically, by testing and adjusting Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels. Symptom relief should be all important to you, not just test results. You can get some good insight into clinical treatment from this letter written by a good thyroid doctor for patients that he sometimes consults with from a distance. The letter is sent to the PCP of the patient to help guide treatment.
http://hormonerestoration.com/files/ThyroidPMD.pdf
Hi
Starting on a gluten-free diet may help some persons in reducing their anti-TPO levels.