What to do about ulnar pain - C6 root damage?

I have Sjögren's - previously diagnosed with RA then changed to inflammatory arthritis then primary Sjögren's. My RA-type pain started 7 years ago in wrists and knees. Always had trouble with right ulnar pain for 2 years but it eased up finally with Methotrexate and physio therapy and has never returned until now. Lots of other bits of pain. I do have confirmed Osteoarthritis in my lower back, fingers and neck.

A neck MRI apparently showed C6 root damage 3 years ago. Does anyone know if this could be causing this pain and stinging pins and needles down my outer arm into my fingers.

Since starting my 4th immunesuppresant, Mycophenolate, 10 months, I've been cheered to find that the knuckle pain in my pinky and index finger knuckles has gone. But suddenly I've started getting a stabbing pain right in the wrist and it's tender if I squeeze it gently. I also have a stinging pain in my pinky knuckle. I have lots of small fibre neuropathy and tendinitis everywhere - so not sure if this is ulnar nerve pain or arthritis or tendinitis? Nerve conduction tests have always been entirely normal.

As i am right handed I'm wondering if this is same as repetitive strain injury? - in which case should I get my husband to massage it or is ulnar nerve entrapment different?

And should I be using a splint to prevent it worsening or is this going to have the opposite effect can anyone advise? I'm not due to see my rheumatologist again until December or my neurologist until April so all advice on how to manage this would be welcome.