Rapid weight loss, cold intolerance, fatigue, dry skin, watery eyes

[EH_WI]

I have had a number of concerning symptoms over the last two weeks.

Here's a list of some of my symptoms:
-Weight loss (12 pounds over 4 weeks with no change to diet or exercise)
-Cold intolerance (need multiple layers and blankets even when it's 75-80 degrees)
-Night sweats
-Fatigue
-Blurred vision in both eyes (typically at night, to the point where I cannot watch tv or drive)
-Constantly watering eyes
-Dry skin
-Numbing of hands in mornings and evenings
-Depression
-Slight hand tremor (always present but worse)

I have been to the doctor to get an assessment and blood work, but they did not have any answers. All the blood work came back normal. They tested my thyroid hormones, and everything came back within range:
TSH: 1.39 (Range 0.465-4.680); T3 Total: 102ng/dl (Range 97-169), ThyROXINE, FREE: 0.83 ng/dL (Range 0.78-2.19).

I should say I have been experiencing these symptoms about twice a year for the past few years. Initially I believe it was tied to alcohol misuse, depression, and anxiety, but those items have been under control (I'm over 1.5 years sober). Additionally, this go-round the symptoms are lasting longer and are more intense than previously.

Any thoughts or recommendations are appreciated!

[Red_Star]

Free T4 is quite low in the range.  I have Hashimoto's thyroiditis and I only feel well when my free T4 is in my sweet spot of 16 pmol/l (10 - 20 pmol/L).  A more indepth testing would also include free T3 and thyroid antibodies - thyroid peroxidase antibodies and thyroglobulin antibodies.

With Hashimoto's thyroiditis you can have episodes of hyperthyroidism - called hashitoxicosis. I had this on and off for four years from leakage symptoms of active Hashimoto's thyroiditis and once for two months due to Graves antibodies also showing up causing major hyperthyroid symptoms.