Back issue

I have had right sided middle back pain for a few months now.

I was told it could be impinged nerve so i have had blood tests done, CT scan and an MRI scan.

All clear so i have been told its a muscle/ligiment strain.

But i have seen an oestepath and had pyhsio for 2 months now and the pain isnt getting any better.

I can have one or two days with no pain, then a week in aa lot if pain.

I cannot lay on my back or right side in bed , and being in a car causes it to flare.

Does anyone have any idea what it could be or is it just old age.

Im 51 manual