I often take painkillers (acetaminophen aka paracetamol), but I’ve noticed that it’s much more effective if I take them TOGETHER with my ADHD medication (ritalin aka methylphenidate) + my morning coffee. If I don’t take them AT the same time, the painkiller is far less effective.
I do not exceed the maximum dosage of painkiller (1gram per intake, mornings), but alone this would barely suffice to kill my morning headache.
My hypothesis is that since the LIVER has to convert all three, I am effectively overdosing on either substance (painkiller or ADHD meds), and damaging my liver in the process.
I have some chronic pain issues as well, some of which were solved and some are managed. I’m sorry you’re going through this. Have you tried getting a second opinion or maybe a different type of medical provider? I had headaches as well that turned out to be largely brought on by stress and also some bad posture. I did get an MRI+MRA just to be sure nothing was actually wrong in the brain itself, but techniques to reduce the causes were helpful to me. Good luck!