What should I do if I still can't work due to a work injury that got worse because of an auto accident that was not my fault?

I got injured on the job 4 months ago. I have been out of work since. I had a shallow disc bulge and the doctor says my pain is nothing but muscle problems. I have had MRI and X-rays taken. I have done several weeks of physical therapy and couldn't tolerate work. When it comes to hardening physical therapy, the therapist said that I was not ready for it and that I could benefit from further medical treatment on my next doctor's visit. He said I had reached maximum medical improvement, sent me back to work with no restrictions and gave me a 0 percent rating. I am still unable to lift hardly any weight, walk for long distances or stand for long periods of time. My job is a very labor intensive job and requires a lot of heavy lifting, standing, walking and working for up to 10 hours a day. I have a second opinion with another doctor in a few weeks. But yesterday, I got into a bad wreck. My wife was driving with me and my 2 kids in the car. We were at a complete stop when someone ran into the back of us. He was going at least 30 mph. My wife and I were rushed to the hospital in the ambulance. They did a CT scan and said nothing serious, just a muscle strain in my back. But I am certain that this wreck has done more damage to the problems I am already having from my work injury since I haven't healed from the work injury in the first place. So if the second opinion from the doctor from my workers comp case says that I need to continue physical therapy and I will more than likely need physical therapy for my wreck injury, how do I go forward with both of these cases with the same injury, one injury making the first injury worse? Will they discontinue my workers comp claiming that the only reason I am not able to work is because of the wreck? Can they say that the wreck did nothing and that my injury is only work related? Can I prove that both of them have contributed to my disability? Please I need some advice after 4 months of having only a portion of what my pay check should be and then having to take out 2 personal loans.