Maybe a good place to start is by noting that in the untreated state your body was used ot a continuous low flow of thyroid hormone throughout the day. When taking replacement thyroid hormone, all in a large dose, it spikes T3 and T4 levels and tends to suppress TSH for most of the day. If you get your blood drawn for thyroid tests after taking your daily dose, that tends to give false high results. So you should always defer your morning dose of thyroid med until after the blood draw. This is in accordance with the AACE/ATA Guidelines for Hypothyroidism. Most doctors don't know this or don't care, so they don't mention it.
So what time did you take your thyroid med and what time was the blood draw for those last tests?
In addition, many people find that taking thyroid med that is adequate to relieve hypo symptoms creates a different relationship among TSH, FT4, and FT3. The frequent result is that when the dose is adequate to relieve symptoms, TSH is suppressed below range. Doctors don't understand this and try to adjust your dose based on TSH, rather than as needed to relieve symptoms. This doesn't work for most hypothyroid patients.
A good thyroid doctor will adjust thyroid medication as needed to relieve hypo symptoms, without being influenced by resultant TSH levels. Symptom relief should be all important, not just tests. Most of us have found that if we defer the med until after blood draw, we needed FT4 level to be around the middle of its range, and FT3 in the upper third of its range, and adjusted as needed to relieve symptoms.
Also, hypothyroid patients are frequently deficient in Vitamin D, B12 and ferritin, so you should make sure to test for those and supplement as needed to optimize. D should be at least 50 ng//ml, B12 in the upper part of its range, and ferritin should be at least 100.
If you want to confirm what I have said, click on my name and then scroll down to my Journal and read at least the Overview of my paper on Diagnosis and Treatment of Hypothyroidism: A Patient's Perspective.
Also, for the first time, the effect of Free T3 on symptoms has been quantified. Have a look at this link and then scroll down and click on Fig. 1C, to see the effect of different levels of FT3 on the incidence of symptoms (note the numbers are in pmol/l, with a range of 3.1 - 6.8), so not directly comparable to your results
Your Endo is treating you as they normally do, which doesn't work for many people. Your test results from 2015 confirm you have Hashimoto's Thyroiditis. With Hashi's the body erroneously identifies the thyroid gland as foreign to the body and produces antibodies to attack and eventually destroy the gland. As this is happening the FT4 and FT3 levels go down, and the pituitary produces more TSH in an attempt to stimulate more production of thyroid hormone. Obviously at that time a doctor started you on thyroid med; however, if you compare the two sets of results, your latest FT4 and FT3 levels are actually worse than in 2015. How are you supposed to be okay now????? Clearly you are not, you have all those symptoms.
There is a lot to discuss, but first please tell us your thyroid med and daily dosage.
Also can’t retain information very well
Current levels April 2020
TSH 1.08 mIU/L (0.2 - 4.2)
Ft4 15.6 pmol/L (12 - 22)
Ft3 3.2 pmol/L (3.1 - 6.8)
Private thyroid panel June 2015
*TSH 5.2 mIU/L (0.2 - 4.2)
Ft4 19.2 pmol/L (12 - 22)
Ft3 4.0 pmol/L (3.1 - 6.8)
*Thyroglobulin antibody 275 IU/mL (0 - 115)
*Thyroid peroxidase antibody 58.5 (0 - 34)