You should see endocrinologist ASAP. That happend to me almost 5 years ago, my mother cardioloyst was the one that notice my "big neck" already with 3 nodules and hypothyroid, before that I had a year of false negatives in all Thyroids test results. Finally a year ago my endocrinologist diagnost me with Hashimoto's... Is a long journy to find the right diagnost.
What thyroid labs have you had done? TSH, Free T3, Free T4? Those would indicate a need for medication, more than a nodule.
Your symptoms indicate that you are hypo, so if you can get those tests done and post the results, along with reference ranges, since these vary lab to lab, member would better able to comment your specific situation.
An endo is not required for treating thyroid issues; many people find that they do better with a pcp, since many endos center their practice around diabetes, rather than thyroid.
Since Endocrinologists deal with the thyroid and metabolism, I would start there. Sounds like he masked the problem, not solved it.