Did my doctor commit medical malpractice? What are my options?

I was injured on the job by a co-worker. I have three bulging disks in my neck as a result. The chiro was not able to adjust. The massage therapist (3 visits) was only able to apply ice because of swelling. Physical therapy 3x week for 4 weeks and he was only able to use electrical stim and ice. The neurosurgeon wanted surgery. I was sent to an IME. They claimed I had a pre-existing condition. I've had no previous neck injuries. Then my Occ MD released me for light duty and said, "I know you have a ligitamate injury. However, I am going to release you." I received no explanation. I asked for a refill of pain meds and she wrote me a prescr. for 40 Vicodens. Should she have done this? I run heavy equipment. Is this malpractice? I'm hurting and cannot work. This has severly affected my intimate relationship with my husband.