hi, Judith80. The nodules are probably benign, and caused by the reflux. Erosion caused by the reflux can cause cancer which radiofrequency can usually eliminate. The source of trouble is the hiatal hernia. There is interesting speculation that low thyroid can cause disturbance in the esophageal sphincters and contribute to development of a hiatal hernia.
It does sound like you are onto this early in the process. and will find resolution.
Worry is only good when it makes you investigate. You might collect records today. Get notes on the haitus--how large it is. Get the physicians notes on the throat exam, exactly where are those nodules, on the vocal folds? How underactive is that thyroid are you clinically insignificant. Have you had a serum TPO to see if the thyroid issue is Hashimoto's.
Keep us posted.