I don’t usually tolerate meds, but low dose naltrexone, LDN, has been helping me a bit with fatigue since October. I minimized side effects by starting with 0.07mg. (I re-encapsulate myself.) It is a med, an opioid antagonist, that is maybe more for brain fog and fatigue, and for pain only for a few, see this 2023 study.
milnacipran/Savella has been FDA approved for fibro since 2009, so the newest of the 3, but the other 2 were approved 2007 and 2008. Of these 3 it has the worst track record. Nevertheless a few people have a little success with it.
I summarized a 2022 study comparing these 3 with amitriptyline here:
Reading this might help you more specifically than if any one person says it helped them or it didn’t, cos they might have a completely different set of symptoms than yours. Like with all treatments we try. That study tries to show which set of symptoms these drugs might be best for.
(The only one of these I tried was amitriptyline, with 8 side effects after 4 months. And I and my docs are sure I wouldn’t tolerate the others, like I didn’t tolerate any pain killers or they didn’t do anything.)