I use a mix of Naproxen, paracetamol and effervecent 30mg codein/500mg paracetamol. If I have a flare up I need to start counteracting the inflammation and the pain early on with Naproxen. I've found that taking 500mg Naproxen at a time (twice/day) helps better than 4 x 250mg. It seems that the higher dosage works better at counter-acting the flare up. But hey, sometimes (before the lovely Prostap ) I would have to set my alarm on 5.30am, take biscuit + 500mg Naproxen + paracetamol. Sleep an hour, then get up and top up with codein/paracetamol effervecent. Off to drop off kids and then work. Top up with effervecent codein/paracetamol mid morning. Then second dose of NSAID after lunch (as long as you eat something before taking NSAID) and I'm ok until about 3pm-4pm. Nackered/chattered/complete wreck in afternoon/evening but hey - I can at least go to work.. Before recent year of Prostap I was on an average of 750-1000mg of Naproxen/daily (+codein+paracetamol). My pain tend to be chronic with 2 sometimes 3 flare ups/week and instead of sleeping my normal 6hrs/day I slept 10-12hrs/daily.
Naproxen doesn't help when the peak of the pain has already arrived - it prevents & counter-acts rather than turns the existing pain down - for that I use the codein/paracetamol. Like you I find that however much of these I take, during a flare up they only dull the pain. I am so happy that I'm currently back on Prostap but unfortunately cannot take Prostap forever..
If I were you, I would check with GP about your use of pain killers long term especially NSAID. Apparently Naproxen is one of the NSAID that causes the least cardiovascular side effects when used long-term. You will most likely also need to take a PPI to protect your stomach lining when taking NSAID long term.
I have also heard about the use of low dose Amitryptoline against nerve pain and chronic pain. Would your GP refer you to a pain clinic for further help and advice?? I would mention to him/her that the amount of pain you are experiencing is having a detrimental effect on your quality of life and also how it affects your work/career as well as homelife.
Top tip - 2-3 mugs of green tea 3-5 days/week - dulls the pain/turns down the intensity of the pain by 1-2 degrees for me. Started working after about 10 days of regular intake! Green tea is an angiogenisis inhibitor and works by restricting the (wild overgrowth!) growth of blood vessels that supply the growth of endometrial lesions see published material on PubMed ncbi.nlm.nih.gov/pubmed/186...
Take care, look after yourself!