Stress sure does have a lot to do with how tense our muscles are! When my muscles tighten, they pull bones out of place! My ligaments have stretched and didn't return to normal length... some of that is due to the physical injury, but some is due to my muscles staying over tight and...

Low back pain is a common area of distress for a number of mental issues... it's the weakest part of the spine. I use anything and everything to ease it... hot baths, heating pad, stretching (gotta keep hamstrings stretched or it affects the lower spine), ice packs, TENS, and pain med.

I'm sorry you're hurting. Since you're aware, you can find what's causing it, imo! Good wishes.