I can't speak for all jurisdictions but around here, pain medicine is very difficult to obtain. Doctors don't prescribe anything strong unless the need is very high (they're a bit more lenient in the hospital where the patient can't jump into a car and drive off).
I went through a spell of extreme back pain a couple of years ago, where I was literally writhing on the floor in pain. I was finally prescribed 12 Hydrocodone, which helped immensely. I was fortunate in that my pain was muscular in nature and I never had to take the full prescription. I still have 3 doses and despite their being expired, I keep them in case the same back issue arises again. Fortunately, I've been able to keep the back in good condition since that incident.
There were other avenues to be explored before using a powerful drug for pain.
Merck won that case but others will cost Merck big time.
Glad your back is better. My guess is that there is no worse pain.