Hi I am so sorry for all you are going through. You are in my thoughts. I have not read much about this so my thoughts are just that my thoughts. I think you need to speak to your treating doctor asap. Also did they do testing for other reasons or conditions that may have caused this other then being bed ridden? If not I would push for that as well.
I would think that maybe there is some type of movements you are supposed to do even if you are only able to in bed. That to prevent atrophy,sores,and possibly this etc. I know with the pain and the limits you have this is easier said then done.
Sending get well thoughts to you