I have been following your posts. I am so sorry you have had to go through all that, only to be told they cannot do more. Personally I don't believe that. Your letter was wonderful to the doctors involved in your care. I hope they will offer a re-evaluation, and can direct you to someone with the knowledge to help you.
I am wondering if you couldn't have an epidural, that is the kind they use for women in childbirth, that numbs from the waste down. I mention this as I had a friend with cancer of the bone. She was given a continous drip, and she had a great quality of life with no pain. There are also Ketamine infusions, which I have not heard you mention. This has been used in the states with good results, especially used in the military for injured vets.
Can you seek treatment in another location in your country? If this facility has written you off, I hope that you can still go forward in trying to find help.
You are very brave. I wish you all the best in your life. ginnie