I can't speak to its effect on fatigue as I don't have that symptom (unless I over exert and its part of the PEM).
I also don't have pain, so can't comment on that either.
I vape if for anti-inflammatory, pro neuro-genesis, anti-nausea, anti-tumour, pro sense of well being - I also think I read recently it inhibits/breaks down Alzheimer's plaques (and I'm genetically susceptible to that).
I hope its helping my sleep, otherwise I'd get even less.