dear sixpence
doesnt seem fair that you are having your health problems ignored by these professionals, having said that there might be other reasons for the lack of enthusiasm on their part
It is more likely than not that your problems are related to the arthritic changes you have in your spine...unfortunately age is something we cant change...
on the positivee side, your pain isnt constant and it gets relieved by a position so there is hope...
I would suggest you try your hands on acupuncture and perhaps consider private treatment if you can afford it...
im suggesting acupuncture because i believe it would help in curbing the pain as well as getting the muscles relaxed first..unfortuntely yoga exercises and all exercises in general will only work if the range of motion is available anatomically otherwise you can cause more damage by forcing any stretch or range...
your acupuncture sessions should incooperate, some added massage, advice plus home exercises particularly for your posture, spinal stabilization and flexibility...
Having pins and needles with numbness is not a good sign so i suggest you get assessed quick by a professional for treatment...although your medical history is full (epilepsy, diabetes) im sure a good MSK physiotherapist will be able to assess how suitable you are for this...
I have seen people with degenerative backs who are practically bent over and needing a stick or frame to walk and could barely cover the distance of their bedroom to toilet suddenly discard their sticks and walk into town after two or three sessions of acupuncture so its worth having a go at it