Warning long TLDR: I’m in a lot of pain and sleepless, how do I convince my Doctor to help me and prescribed something helpful?

So I’ve been diagnosed for 6 months, has symptoms for 2 years, I also have anxiety and depression. I’m in the UK so see a GP (pcp in us) who when diagnosing me tried to refer me to rheumatology but they declined my case and told my GP just to diagnose me herself if she suspected fibro.

I’ve been on duloxetine (cymbalta) 120mg for 3 months after stepping up from 60mg which I started 7 months ago. This hasn’t helped with my pain at all but does help my anxiety and depression. I take paracetamol 1g 4 times a day, Ibuprofen 400mg 3 times a day, and supplements 150mg of magnesium once daily, 5-htp 100mg once daily and an adult multivitamin once daily. (I also take Fexofenadine 120mg once daily for hayfever and testosterone gel daily as I am ftm transgender)

Sorry for rambling I’m very foggy. My point is I’m in a lot of pain ranging from 4-8 as well as sleeplessness and headaches but my GP seems reluctant to prescribe stuff to help for fibro. When I got sciatica 2 months ago they happily prescribed codeine 30mg and diazepam (both temporary because of addiction risk) but for my fibro they don’t seem to want to try anything accept antidepressants when I know there’s options that aren’t narcotics etc. They also keep dragging their heels saying they’re waiting for me to see the pain management clinic but I applied in December and still haven’t heard anything. My question is how do I tell/convince my GP to help me?