George,
Are you insulin resistant? You can tell by the size of your insulin dose. If you are, even though you are a Type 1 you would benefit from using Metformin which would cut down the amount of insulin you use and stop weight gain and make it much easier to lose weight.
Symlin might also help a lot, as it affects eating patterns and also cuts down on how much insulin you have to use.
I’ve written extensively about this same topic, coming from the other side–diagnosed as Type 2 but I was diagnosed with "prediabetes: when I weighted 108 lbs.
There’s nothing that says that someone with insulin resistance can’t develop an autoimmune disease too.