Many of the things you have listed are associated with acute hypothyroid conditions. It is time for you to have an endocrinologist evaluate things and make recommendations. Also while you are now a year out, the timing is right for this to really kick in. Radiation can also affect a variety of other things especially in nasopharyngeal cancers. Nerve damage from the radiation can affect your inner ear causing vertigo (benign but distracting) and in my case I have progressive deterioration of many of my facial nerves from my radiation treatments which in the long run will cause me to have loss of control over portions of my face and neck. Radiation can induce many side effects, so besides your thyroid, do not rule out these things. But aren't you about due for your annual scans to see how things are? These scans might reveal if there are any additional problems occurring.