Had on going issues with my lower back. I've had Acupuncture (you barely notice the needles tbf), Chiropractic and Physio.
If you want quick pain relief/repair, go to a Chiropractor. Cracking your back in well help the initial pain, but not address it fully long term. To work on it, I recommend going to a Chiropractor who does low impact Chiropractic. Basically they tap your nerves and this forces your spine to adjust itself (which in theory will fix it long term). Make an ACC claim (impact is the key) and this should help with the overall cost.
Physio I found was a waste of time, I could just google exercises online.
Acupuncture releases some tension which helps, but doesn't address the underlying issue.
Recently bought my own chair for work and the issues have dramatically decreased. Found out that the chairs we were sitting in are designed for 4-6hrs - I wasn't even aware that was a thing for chairs. I could've saved myself a lot of money and pain if I had bought a new chair earlier.
Hope this helps.