You need to be reffered for thyroid ultrasound, so the nodule will be measured and described (can be just a cyst). If ultrasound report is suspicious, then your PCP will reffer you to ENT or Endo, depending on what you need. ENT is better for thyroid surgery, Endo is better to treat any thyroid conditions.
Many of us have thyroid nodules and they don't need any type of treatment, unless their characteristics are out of the ordinary. An ENT usually only does surgery, whereas the endo actually treats thyroid conditions. Many ENT's and endos require a referral from your pcp.
That said, have you been diagnosed with a thyroid condition? If so, which one? Are you on medication of any type for it? If so, which one, at what dose?