marine w/ work-related injury

I am an active-duty U.S. Marine living/working in Okinawa, Japan with a work-related injury (lower back problems). Knowing but ignoring my doctor-ordered "light duty," my superiors ordered me to perform tasks which further complicated my injury (three times). Now, after four months, I am undergoing conservative treatment (physical therapy: traction and basic strengthening exercises), and have been told that I will probably see a neurosurgeon for an MRI and an evaluation in the up-coming weeks. As of today, I have been told by doctors that I probably have a bulging (possibly herneated) disk and that only an MRI will show for sure. I have lower back pain and pain down my left leg. Consequently, it is painful and difficult for me to accomplish the basic requirements of my job -- and even daily routines such as getting dressed, cleaning, etc.

My question is, what are the legal grounds for my medical discharge from the military (under honorable conditions) while receiving appropriate disability pay, separation pay, and guaranteed medical treatment in the civilian world? Is there a precident for this? Under the circumstances, I do not trust the military to look out for my best interests; what sort of lawyer, if any, shoud I seek? Will outside legal action on my part hurt my chances of speeding up this process or reaching an agreeable outcome?