I have fibro, raynauds, sjögren's. Why do I feel what feels like deep bone pain. Stinging sharp and dull severe pain?

Nerve pain, likely. Sounds like "nerve" pain, not bone pain. 1. Nerve roots' blood supply may become compromised in immune disease that involves blood vessels; or: 2. "small fiber" nerve disease (rsd/crps); or: 3. Compromised blood supply (ischemia) due to the small arteries spasm; or: 4. Blood clots (autoimmune disease is often thrombogenic); do coagulation study.