What do I do if I will not be able to work for the rest of my life, as well as pay for my future surgery on my own?

Previously, I was hurt on a rig and has pulled worker’s compensation from the workers compensation case and now handling themselves. I feel they are giving me a really hard time. They won't let me return to work once released by the doctor. They are stating their doctor gave me a low rating. However, I have never seen their doctor whereas my doctor explained to them I will be unable to return to work, in addition will need future surgeries, as well as physical therapy. He gave me a high rating. Their attorneys are wanting me to relinquish all of my rights for medical. I had my foot crushed, in addition to hurting my leg and back. They are trying to force me to take forty thousand dollars and walk away.