Undiagnosed pain- any answers?

I was in an accident three months ago that resulted in pain behind my right shoulder blade that has persisted, and has gotten worse. After the initial accident, my pain scale was at about a 3, but within a couple of weeks it got much worse. My primary care physician said that it was probably a muscle strain, and prescribed muscle relaxants. The medication made me sleepy but did nothing to relieve the pain. After calling and calling my PCP to figure out better treatment options, he prescribed 800mg Motrin and referred me to PT. The physical therapist suggested a steroid taper to reduce any inflammation, because all of the exercises he was trying were making my pain much worse. After the steroids, I felt no significant difference, and PT still wasn't successful. The physical therapist referred me to an orthopedist who specializes in nerve problems. I have been on: Neurontin, Ultram, Meloxicam, and Cyclobenzaprine with no results. I'm now on Lyrica instead of the Neurontin, and I still don't feel a difference. I hardly ever take the muscle relaxant, because all it does is make me exhausted, and I don't want to have to take any stronger medication that will throw me for a loop during the day. But at this point, I don't know what to do. My current doctor is diagnosing this as 'cervical radiculitis' because MRIs of my cervical and thoracic spine have both been clear, and an x-ray of my shoulder was also clear.
The pain I'm feeling is not in my neck or spine at all, it is only around my right shoulder blade. The main points are along the edge of my shoulder blade and slightly under it. Not at all on the top of my shoulder or along my spine, just on my back along the shoulder blade. The pain is a constant burning ache, with occasional stabbing pain if I overexert myself. Several times, I've felt some pain down my right arm, but that is only sporadic. The only thing that has helped is a TENS unit, and I've been wearing it all the time. But as soon as I take the TENS off, it's just as bad as it was before. I have a hard time sleeping, and every time I exert myself too much I'm in a lot of pain. The pain level is staying at a steady 7-8, and sometimes goes up to a 9. The doctor told me that the next step is lidocaine injections into the nerve structure around c5-c6 to see if that resolves the pain, and then if it works, a cortisone injection in that area. But at this point there is nothing definitive on the MRI to tell them where to inject for sure, this is just a guess. I am desperate for any other diagnostic tools that could help give me a real diagnosis, so my constant pain is explained! I also want to know what treatment options I could have, because I want to know that this will eventually be resolved, and without a firm diagnosis, I don't know where this is going. Any suggestions or help would be greatly appreciated.
Also another question- when they did the x-rays, they did them from the front. Shouldn't they have been done from the back? For one view, I was laying on my back and my right arm was stretched across to my left shoulder, I guess to extend the shoulder blade out. But shouldn't those views have been done from the back?
Again, thank you for any help.