thyroid issues–nodule?

Toxic multinodular goiter, normal blood work but having symptoms?

My doctor keeps saying that my blood work shows everything is normal and to re check in 6 months. I have a fairly large toxic multinodular goiter on the left side way down at the bottom, near my collerbone. I did the fine needle biopsy (inconclusive), thyroid ultrasound, and uptake scan. The scan showed is was for sure a hot nodule. My doc is waiting around for me to become hyperthyroid before doing to radioactive iodine treatment. Problem is..within the last month I am having many hyperthyroid symptoms. Palipatations, high resting heart rate, extreme fatigue, frequent bowel movements, sweating, nervousness, and i also have horseness on and off during the day. But as of last week my TSH, T3 and T4 still show in the "normal range".
Now my primary care doc has put me on atenolol for the heart issues.

Why would my blood work be normal yet im having symptoms?