Have they run any other tests of your thyroid?
In particular T4 and T3? If these are low, then you have central hypothyroidism. Pituitary related.
I've noticed that doctors tend not to consider central hypothyroidism, which if you believe the AACE white paper is around 20% of all cases of hypothyroidism. If you have indications of central hypothyroidism, then an endocrinologist should check your other hormone levels.
my TSh is 0.1 but i am hypothyroid and have cold nodule