Bit late, I'm afraid, Bergs. Meant to write this a couple of days ago.
First, over 50 yrs ago was getting severe back pain regularly (caused by too much leaning over car engines, I presumed). Would be in agony for a week, unable to get out of bed. After several episodes, my doctor at the time (one of the 'old' brigade) suggested a well-known healer - a short, round-faced bald fellow. Sadly, he died 40 or more years ago.
Was a nightmare journey to his house in my Mk2 Cortina. Arrived, and stood just inside his front door. Told him I suspected a disc issue.
He touched my head and disappeared into a back room for a minute or two then re-appeared. I asked him what was wrong. He simply replied that I was alright, and I left. From that moment on, my back has never caused a problem. Don't ask me how / why anymore than if I understand water-divining (yep, can do).
Secondly, have you tried a decent osteopath? Approx 30 yrs ago was getting muscle pain, so saw a local osteopath (retired SBS man) and he sorted my issues (mainly leg / thigh). Remember he once told me of a patient (doctor) he saw regarding back pain. He asked if the patient had been playing golf at the weekend. Somewhat bemused, the doctor said 'yes'. Osteo then asked - did you twist your ankle? Doctor, bit stunned for words, said 'yes'. Osteo then pointed out the sciatic nerve runs from the ankle to high up in the back, and where you feel pain is invariably not where the problem is.
Thirdly, after my friend osteopath died, ended up seeing doctors re various muscle pains. Recall seeing one referral nurse, who, after nearly an hour's discussion, suggested attending a Sunday group where everyone could discuss their worries. About as much use as a gallon of petrol as a fire extinguisher. Was at that time I noticed a large notice on the wall - about 3ft x 2ft - that said 'There is no cure for back pain'. I left pretty quickly and asked around for a good osteo. Found one, though one of his employees is better. A nerve needs manipulation, and a round with this guy is like a round with an angry gorilla. But it works. A day or two later and you're back to 100%.
I'm no doctor, Bergs, but I'd suggest a good (not hospital type) osteopath.
And good luck.