Two possibilities to mention:
1. If your skin is tender to touch and burning is not affected by body movements and different positions, then it can be shingles (Herpes zoster virus reactivation in one of the spinal nerves). Nausea can be also from shingles. This causes burning pain going like a stripe from the spine to the front. Often (but not always) rash appears after some time. Neurologist would tell you, if there is any available painkiler for your situation.
2. Bulging or herniated disc or some other disorder in your thoracic spine (osteoporosis, arthritis..) could cause pinched spinal nerve. This type of pain would be affected by different body positions and would not be tender to the slight touch. Again, neurologist could say more.
Pain is generally an unpleasant feeling in response to an event that either damages or can potentially damage the body's tissues. There are four main steps in the process of feeling pain: transduction , transmission, perception , and modulation .  The nerve cells that detect pain have cell bodies located in the dorsal root ganglia and fibers that transmit these signals to the spinal cord.  The process of pain sensation starts when the pain-causing event triggers the endings of appropriate sensory nerve cells . This type of cell converts the event into an electrical signal by transduction. Several different types of nerve fibers carry out the transmission of the electrical signal from the transducing cell to the posterior horn of spinal cord , from there to the brain stem , and then from the brain stem to the various parts of the brain such as the thalamus and the limbic system . In the brain, the pain signals are processed and given context in the process of pain perception . Through modulation, the brain can modify the sending of further nerve impulses by decreasing or increasing the release of neurotransmitters . 
Hi, are you feeling better? I hope so but if not, have them check you for Pheochromocytoma (tumor on adrenals) They test your catecholemines (norepinephrine, epinephrine, dopamine) in 24 hr urine test (not just the blood draw) Also, have they checked for both thyroid antibodies? Peridoxidase AND Thyroyglobulin, they often don’t check for the second one. (Hashimoto’s)
Do you have higher calcium levels? I believe that may mean a tumor on your thyroid but I don’t know what test, they use for that one. Most of these tests won’t show up on a regular blood test, doctors only seem to do a few standard tests and then rush you along, it’s frustrating.