Chronic back pain
should be evaluated properly and causes for chronic back pain are millions.
with respect to you a long standing back pain not relieved with pain killers and physiotherapy
should be further investigated before conforming the diagnosis.
If it is Spinal tuberculosis
you should also have loss of weight, loss of appetite with low grade fever
and spinal TB most commonly affects the thoracic( chest level) vertebra.
It is advisable to do a MRI
scan of the vertebra before conforming the diagnosis and treat accordingly. In mean time continue physiotherapy , pain killer and life style modification like avoid lifting weights, avoid sitting in improper posture.