The pain I have in my legs feels like it is coming from the bones, but nerve pain plays tricks on you. I do have progressive muscle weakness as mine is a hereditary sensory-motor neuropathy, so at least some of the pain is from trying to function with weakening muscles.
I have lost most of the range of motion in my ankles much as you describe. After a sprain last fall we worked on this at physical therapy and it improved a little, but then we hit a wall because that is how this disease works. I walk so far in on the insides of my feet that I am getting leg braces to protect my ankles, correct my gait, and give me a little help with foot drag -I am unable to move my toes or the front of my feet.
Do you know what type of neuropathy you have? Have they evaluated you for muscle weakness?