Provided the blood test does not show a low TSH, the next step would be FNA biopsy of the 3.4cm nodule and possibly the 11mm nodule (depending on ultrasound characteristics).
With the comment about heterogeneous thyroid, there may be Hashimoto's -- so in addition to TSH, we would consider testing TPO and Tg antibodies.
90% of the time, nodules like yours are benign.
Thank you dr. I feel more relieved.