I second the recommendation Kells made.
I assumed my throat/chest pain and difficult swallowing (a year after my Graves diagnosis and two months after RAI) was thyroid-related. It turned out I had developed severe GERD (acid reflux) and a constricted esophagus. Both my endocrinologist and gastroenterologist attributed my sudden GI issues to my fluctuating thyroid hormone levels. I have not heard a lot about it on here, but both physicians told me patients develop GI issues when their thyroids are not controlled for a long period of time. Fortunately, reflux is easy to treat with PPIs like Prilosec or Nexium. It might be worth seeing your endo as well as your primary care physician to rule out any GI issues.
We tend to attribute any new symptom to Graves, when sometimes it is completely unrelated, or related but not a direct thyroid issue.