Meaning For Thyroid Ultrasound?

My Thyroid Ultrasound shows diminished size of the thyroid gland. Its 4.5 mm but perfect in shape. my tests results were : tsh 2.70 FT3 2.84 Ft4 11.1 ΑΘΑ-T 10 anti-TP) 10 and then i had 25 mg of Medithyrox and the next results after a month were TSH 2.46 ft4 9.97 Next results Medithyrox 50mg TSH 1.85 ft4 12.1 . I also had 1 : iron 42 mg 2 :78 Ferritin 26 and 3 : 66mg iron . The 3rd results after the intake of one FERRO SANOL DUODENAL 100 mg per day. The first doctor said I should continue with the theroid pills. But the second sain that I need no pills. Then I had a month without getting medication and then I had new tests and the results were : TSH : 3.9 Μiu/ml T3 :.1.54 ng/ml T4 : 2.1μg /ml Anti-T : 2 IU/ml ANTI-PO : 18 IU/ml B12 : 349 pg/ml I am 30 years old, 1.67 m tall and I weigh 54 k. I never had obesity problems, the opposite I could say. I had the thyroid test because of the fatigue I felt and my mood changes. I don’t smoke or drink, and I exercise regularly. Thank you very much for your time and your help.