Sounds similar to my journey in some ways. I'll share a bit on the off chance that some of my experiences might be useful.

I always had headaches and mental health struggles. Hopefully you don't. I sought help for both. My mental health issues were misdiagnosed (I'm AuDHD, the other stuff mostly stems from that) and for the headaches I was just told to lose weight. Easier said than done, and the headaches got worse while I tried. I used pain meds and developed chest pain that got diagnosed as heartburn. Prescription omeprazole (prilosec) keeps it in check.

I finally lost enough weight for them to take the headaches seriously and get referred to a neurologist. We can't be sure of the exact cause, but a good bet is anxiety - a very sensitive/overactive nervous system as a result of C-PTSD and autism. I take topiramate to calm it a little, edibles 1-2 times a week, quarterly injections, and I do a somatic meditation. This is a great exercise for pain without a physical source, caused by things like my overactive nervous system.

If your pain is made worse by anxiety, it may help to get in the habit of practicing a quick somatic meditation focusing on the pain whenever you experience it. Otherwise, just keep advocating for yourself until you find a doctor that will help. I hope you find something that works for you soon.

Also, on brain meds: they're all multi-function, so if it's anti-anxiety that's more of a happy accident. They wouldn't give you a nerve blocker just for anxiety. Side effects tend to lessen the longer you take the drug, but not always, and the time scale is a bit different for each. At 2 weeks it should be starting to get better, at a month if it's not better it's probably not going to get much better. Hang in there!