Your story reminds me a lot of my mother's, except hers is a lot less severe. I thought, however, that I might pass on things that have helped her just in case you think they might help you too. They are not cures, per se, but have given some symptom relief so that she is able to tolerate more.
The first is Chinese medicine. She cannot tolerate the herbs or much acupuncture, but has found a Chinese doctor ( from China, and third generation - and I think that is the part that makes a huge difference) who massages her twice a week. I have also received massage from him, and what he does is very gentle stroking not massage as you would traditionally think of it - while it is happening it feels like nothing. I have similar symptoms to my mother, but much more subtle. After these massages, I feel like my head is more put together and my body is more stable. My mother is able to go out on her scooter sometimes after his treatments, as opposed to staying in bed for the whole day.
The other thing she has had relief from is homeopathy. I understand that this is a controversial topic, and many believe that it does nothing, but that is not my experience.
In both cases, I believe it is very important to find people that really know what they are doing so that they don't make you worse, and to follow your instincts on who can and cannot help.
Neither of these are reliant on you digesting anything or introducing anything new to your blood supply, and so I thought they might be of interest?
I really wish you the best and hope that you find relief somewhere. I think you are very brave to keep fighting the way you are. It must be so hard, I can't imagine.