Hi.
Thanks for your query and an elucidate history.
Read it and understood your problem.
From the history you have provided - 4 years pain , increased 1 year, unbearable, left upper quadrant, and most important '' sensitive to touch' i too can think of a neurological problem.
I would advise you the following:
Get an opinion of a
Neurologist for confirmation.
MRI of the thoracic spine to see whether there is any compressing disc slips. Or any other problem of entrapment.
Was there any history of
herpes zoster in the past, as post-herpetic'' neuralgia is one of the important reasons for such type of pain.
The probable treatment is :
A trial with
gabapentin works well. this will be a diagnostic test as well as a therapeutic tests and part of the treatment schedule.
Surgical Neurectomy is a small surgery with a chance of
anesthetic patch.
If there is protruding disc , a formal
discectomy will be needed.
Take care , get well investigated and treated accordingly.