Your symptoms of fatigue
are due to hypothyroidism
Since there is a deficient production of thyroid hormone,it has to supplemented from outside and that too for life.You would start feeling the effect of medicine in 4 weeks time and all your symptoms due to hypothyoroidism shall take 4 to 6 months to settle.
You are correct that the correct dosage has to be titrated by regular estimation of TSH levels every 4 to 6 weeks and modifying the dosage accordingly.
There is no need to develop any anxiety
or stress due to your hypothyroidism.