I have ANA 1:640, flares joint swelling w/redness, photosensitivity, rashes, sharp chest pain, raynauds, chronic dry mouth, eyes. Sed and CRP always neg. Why?

Lupus. Lupus is a chronic, autoimmune disease that can damage any part of the body (skin, joints, and/or organs inside the body). Chronic means that the signs and symptoms tend to last longer than six weeks and often for many years. In lupus, something goes wrong with your immune system, which is the part of the body that fights off viruses, bacteria, and germs ("foreign invaders, " like the flu).
Lupus still likely. I am sorry that you have these troublesome signs and symptoms of lupus with likely sjogren's. There is a saying among pathologists that a three-legged dog is still a dog, and that a wise physician focuses on the patient rather than the numbers. The sed rate is the easiest of all lab tests to do wrong, and i've never set much by CRP for anything. Hoping you & your rheumatologist find what works bst.