How was your MG diagnosed?

I have been struggling with debilitating fatique, muscle weakness and pain for many months. I can't even bring in my own groceries at this point. I've had bloodwork, x-ray, echocardiogram, CT scan with no diagnosis. I had a neighbor who was stricken with MG in her 50s and I remember what she went through and my symptoms seem the same. If anyone is willing to share how your diagnosis was confirmed it might save me from having multiple unnecessary tests. Thanks so much!