I would definitely see an endocrinologist about the fluctuating thyroid hormones. Often, if you get the thyroid under control, the MG settles down too. They make each other worse.
Most MGers get a scan of the thymus. There is a small possibility of a thymoma so it should be checked out.
I am a diabetic too. I am monitoring my blood sugar am I am doing surprising well on pregnisone. But there are non-steroid immunosuppresants like cellcept and imuran that a lot of MGers use successfully. Mestinon only provides temporarily relief, but no real overall improvement. You should ask your doctor about additional supportive treatments.
My swallowing is better now that I am on pregnisone. But previously, I had a lot of swallowing and choking problems. Here is a good video on the proper way to swallow with MG and some good hints about foods and diet changes to help with those issues:
http://www.youtube.com/watch?v=VolCFZre4Ys. I have to think to swallow. Before MG, I could just eat and drink and do other things at the same time like read or watch TV. Now I have to concentrate on swallowing properly when I eat. It is not automatic anymore. And yes sometime it does freeze up and I start to choke on my own salivia. MG makes you concentrate on one task at a time, nothing is easy any more. I have to think to walk to make sure my feet don't start to drag and trip. I have to arrange my day and activities around My mestinon schedule. It is manageable but not easy. I am hoping for some big improvement with the IVIG. I will let you know how it goes. I eat several small meals and snacks now and make sure I eat my big meal an hour after mestinon when I am strongest. This helps me with the chewing and the swallowing.
I hope this helps. How are you doing with the heat? My MG symptoms get worse as soon as it hits 70 degrees. Next week it is suppose to get up to 80 here. I am expecting a few bad days next week. I am still working 4 days a week. I take off Wednesdays to recover. I can't make it through a 5-day work week any more.
Hope you find improvement soon. This forum is a great resource
kathie