I had a lifting related injury years back and just went to the emergency room, got a note for work, and the typical pain/muscle relaxant prescriptions. Was a lumbosacral strain, could barely stand up let alone walk or drive.
I got hired a year later and got insurance. I went to my doctor to have him examine the area. I told him it was lifting related and he examined my walking, sitting, laying, stretching, and just standing. He said, I can send you in for an MRI, but I believe I have a pretty good idea already based on everything I've seen.
He determined the strain was a result of bad form. But, he said that it seems one of my growth plates closed early as I was growing and caused a difference in leg length. This difference causes a rotation of the hips to compensate and act "normal". So, when setting up for deads 3-4 years ago, I was twisted up.
You can imagine, staying stiff and symmetrical throughout will make no difference when everything below the waist is fucked. This allows for no transfer. He gave me a lift for one side, this brings everything back into sync without needing surgery.
This is just a story of my experience with my doctor. I don't think a doctor should simply blow it off as just lifting pains... He/she should care about your health, encourage exercise, and help when you have a concern. Hell, bend over backwards considering their pay and the fact that you're even willing to bring your concerns to their attention. I know many people who have problems and just won't go to the doctor because their scared of what they're gonna say.. they have insurance and all..
I would search for someone a little more willing to help you sir. You deserve better.