I am so sorry your in this spot and I can hear the pain and frustration in your post.
What you need to look for is a Personal Injury Lawyer. Shy is right, they will not charge until the settlement is completed. You are in pain and in our state pain is considered a Medical Emergency yet your employer will not pay the fee that obviously is what your physicians in that area charge for this procedure.
Can you double dip, use the WC amount that applies and the rest on your health insurance?
Gentle Hugs to you.