I had poor experience with NHS physio & very good with a Chiropractor - recommended by my GP with profuse apologies & unhappiness they weren't available as an NHS option.
No 2 bad backs are the same, nor our responses to treatment, what is good for me might be terrible for you.
Go with your gut but keep an open mind & if whatever you pick as Plan A doesn't work, give different things a go until you find the one that does work for you.
one observation on Chiro's as they've taken a predictable kicking again. For all the negativity and dismissing of it you'll hear & read: bear in mind they don't get subsidised by NHS patronage and have to survive on their ability to perform, there are an awful lot of established thriving businesses out there, even in relatively small places. Pretty much everyone at mine had a similar tale of failing to find an answer previously under physio etc and/or for *free* via the NHS.
Why would people keep coming back, paying a good chunk of their own hard earned cash each time for something supposedly ineffective & mumbo jumbo or giving physical relief that is available at no cost to themselves elsewhere?