I was in a similar situation with my back a few years ago. It could be absolutely excruciating. While I also had a protruding disc, it turned out a lot of my problem was hanging on to the mental trauma from the death of a family member in the form of muscle tension. What ended up helping me get better was the combination of therapy (mental not physical) and regular massage appointments. There is also a great book by Peter Levine called "Waking the Tiger" that helped me to understand how my body can carry emotional trauma physically.
Not sure if this relates to you at all but hopefully it helps.

It sounds like maybe it's time for you to see a pain specialist if you haven't already done that. Mine are amazing. They help me manage my meds and any follow-up testing I need, and also work on hunting down the cause of any new or existing issues that could be managed by them. It's so frustrating when it feels like your doctor doesn't understand your pain, and a good pain specialist will not make you feel like that.

I have read some articles from chronic pain specialists saying that it's possible what your doctor is saying has some truth to it, because long-lasting pain can cause changes to your brain that make you feel pain even after your original injuries have healed. I thought that was happening to me, and my doctors probably did too, but I had nerve testing done and it turned out I have a pinched nerve that hasn't been addressed and it is somehow causing my body to experience pain at much higher levels than it should, and I tense up and become a ball of muscle spasms. The human body is so strange.

We have a lot of chronic pain sufferers in this community. You are welcome to join us. It's definitely difficult to manage and detrimental to your mental health, but I don't think your doctor was saying you are crazy. I think they were saying your brain is causing you to feel pain that you shouldn't technically be feeling so strongly anymore, so the problem is still real, but neurological now.

💀