I hope someone can help me on this one

I don't have a family history of diabetes and became a diabetic after a bout with bronchitis. Test after test later, they tell me that my diabetes is autoimmune.
Flash forward 11 years and now they think I have another one. I am having rashes and extreme joint pain so they are doing all of the testing for either Lupus or Rheumatoid Arthritis. I can not even begine to imagine how I would deal with either one. All of this on top of the diabetes is beginning to wear on me.
Is anyone else dealing with more than one autoimmune disorder? If so, how are you dealing with both conditions at the same time? It amazes me that the system that is supposed to protect you can turn on you with such a vengeance