Hey!
I had 'mysterious' back pain (that extended into my hip) that actually worsened if I tried hard to stand straight or exercise (the wrong way)!!
It was really an eye opener for me!!
On another site I also heard this book recommended: Back Care Basics: A Doctor's Gentle Yoga Program for Back and Neck Pain Relief, along with a few others...
Additionally Magnesium is super-important, both for emotional wellbeing & spine health, along with Calcium etc)
Also, occasionally EFT has helped me both on the emotional & the back front.
& yeah, go see & ask advice from a specialist!! both on 'okay exercise' and bed, chair,... This was really helpful for me too!! (I now have a softer bed & sit on an inflatable ball, & it helps!!)
Also, what kind of food are you eating? salted dried pork or sweets or stuff with additives or white flour etc can be bad... Are you taking any supplements, & which ones?