Hi I Am 50 Years Old And I Feel Like

Hi I am 50 years old and I feel like I am loosing my leg muscles I have done blood tests my ra is positive, Ana is positive and there is also another blood test.which was positive I don't remember. I feel like my memory is going too. At one point one dr. Rheumatologist said I might have auto immune disease called scleroderma and there is no cure for it. Let me know what other test I have to do