You are certainly not doomed. But you will have to get your doctor to understand that you need less T4 med and more T3 med, in order to relieve your hypo symptoms, including low metabolism. Since you were given some T3, that is a good sign that the doctor might be willing to give you more, which you need. By the way, some time ago when I was hypo I had very bad acid reflux. I increased my T3 dose and in 3 days it was gone.
If the doctor resists testing for Free T3 and ferritin, then you should use the link above to try and get the doctor to understand the benefit of doing the right tests and treating clinically, as described, rather than just based on test results, which don't tell the whole story..
My mother took nexium and her mental and physical health declined drastically over 6 years. I took her off nexium when I found low stomach acid is usually the cause of reflux conditions and started her on betaine HCL with pepsin supplements and digestive enzyme supplements. Her mental and physical health improved drastically, she got rid of her severe GERD, gastritis pain eventually went away she also lost weight too.
Judging by the range, I'd say no on the FT3, but we can tell for sure by looking at the measurement units shown on the lab report. Is it shown as ng/dL, or Pg/mL? Also, what was the diagnosed cause for your hypothyroidism?
Looking at your test results, your FT4 is at almost 90% of its range, which is higher than the 50% level that works well when FT3 is adequate, which is usually the upper third of the range. If that is TT3 as I suspect, and your FT3 is comparable in range, then that is lower than typically needed to relieve symptoms. It also indicates that your body is not adequately converting the T4 to T3, and your T4 dose is higher than needed, while your T3 dose needs to be increased.
I don't know why your doctor would think you are borderline hyper. Probably because of your high FT4 and maybe your TSH level. I agree that your FT4 is higher than needed, but that does not make you hyper, and TSH should not be used to medicate a hypothyroid patient. Scientific studies have shown that hypo patients frequently have suppressed TSH when taking adequate doses of thyroid med. That does not mean hyperthyroidism, unless there are hyper symptoms due to excessive levels of FT4 and FT3, which you do not have.
A good thyroid doctor will treat a hypothyroid patient clinically, by testing and adjusting Free T4 and Free T3 as needed to relieve symptoms, without being influenced by resultant TSH levels. Symptom relief should be all important, not just test results. In addition to FT4 and FT3 levels there are numerous other processes and variables that affect the desired end result, which is tissue thyroid effects. Among the major ones, you have addressed Vitamin D. You also need to test for ferritin and B12 and supplement as needed to optimize. Ferritin should be at least 100, and B12 should be in the upper end of its range. Vitamin D should be at least 50 mg/mL. It is also good to test for cortisol to make sure it is optimal, since it also affects thyroid.
You can read about all this in the following link. I highly recommend reading at least the first two pages and more if you want to get into the discussion and scientific evidence for all that is recommended. Note especially page 7, which shows all the processes and confounding variables that affect tissue thyroid levels and effects. Clearly a hypo patient cannot be successfully diagnosed and treated based on biochemical tests only. Signs and symptoms are even more important indicators of thyroid status. You may be able to get what you need from the doctor by giving a copy and asking him to review and consider clinical treatment, rather than just based on test results compared to flawed reference ranges ( item 4 on page 5 of the link).
http://www.thyroiduk.org.uk/tuk/TUK_PDFs/diagnosis_and_treatment_of_hypothyroidism_issue_1.pdf
Instead of testing for Total T3 you should always make sure they test for the biologically active Free T3. Free T3 is the thyroid hormone used by all the cells of your body to produce the needed energy. There is much more to discuss, but first please tell us about any symptoms you have besides the weight issue. Also, if tested for Vitamin D, B12, ferritin and cortisol, please post those results.