@Stephy hey I'm sorry that you're struggling with this. Pain ruins people's lives. Often times we don't see it, as these people are stuck inside, in bed or on the couch. It's shitty. I really feel for you. This isn't the end of the road though. If this stuff is not working, there are plenty of other things to try. There are Opioids, partial agonists, Opioids like Tramadol that feature SNRI effects in addition to the Opioid agonism; there is a lot to try.
It's considered very rare, though there are people out there who are "immune" to the effects of Opioids. There are people who get little to no effect from any kind of exogenous Opioid. I don't fully understand the phenomenon. It's so rare that there is not a lot of information out there.
Have you tried muscle relaxers before like Carisoprodol (Soma) or Cyclobenzaprine (Flexeril)? I know a lot of people with severe back issues who benefitted from an adjunct medication to their Opioids. This could also be something like an antispasmolydic (reduces spasms).
Furthermore, a lot of people get actual, general pain relief from Gabapentinoids like Gabapentin (Neurontin) or Pregabalin (Lyrica). For someone with severe issues like yours, it would make more sense to just try Pregabalin first as it is stronger. This could be another useful adjunct to your Opioids.
I'm not sure if you use Cannabis or if you're able to where you live, but it can't hurt to throw some of that into the mix. Cannabis is one of the, all things considered, greatest pain medications known to man. People with severe pain can take highly concentrated oil and many people describe its usage as life-changing.
Factor in your NSAID regimen, maybe some Lidocaine patches and then you might feel well enough to bust out some very basic Yoga or whatever you like (I recommend Yoga 100%). Once you find your pain relief, make sure you use the time efficiently by applying yourself to lifestyle changes that might help with your pain.
So see, you have lots of different options right here in this thread. This is just a short list. There are all kinds of medications and treatments out there. It's my honest belief that you will get through this and get your quality of life back if you push yourself and stay dedicated. I know the couch is comfortable, but too much couch is the enemy.
If you have any questions or need any kind of help, you know where to find us.