As the others said, it absolutely could be that the pain comes from your poor body trying to give you the best situation when you are structurally compromised.
I had severe tightness all over, with pain in my back, my legs, sciatica, my shoulders... the list goes on. I also thought I had knee problems.
The only thing I never thought of during my downward spiral was my hips. Neither did my GP.
I had all sorts of tests, including the innocuously named electromyography, as prescribed by my GP, which tried to figure out why my muscles were so compromised.
That was three hours of torture, as I was punctured by sets of two needles which were then fed an electrical charge to allow measurements. That was repeated many times for all muscles / muscle groups.
They found nothing, which put us back on page one.
I tried all sorts of strategies to deal with my treacherous body, at least three cycles of PT for muscle spasms of three to four months each.
My General Practicioner was nonplussed. Did not know what was wrong.
My last attempt to do this on my own was to take a three month gym boot camp to force my body to buck up. Did not work.
Finally went to see about the hips (this is about seven years into it) and found out the arthritic truth.
Once the surgeries were done (both hips) and the proper recuperation time elapsed (in my case, a full year), I had none of those previous pains and issues. No knee problems, back, etc.
I was blasted by a podiatrist to get better shoes, but I deserved that.
I think you'll find that most issues will go away, and any that remain will be real, honest issues which you can address.
Good luck - best decision I ever made.