i'm no expert, but i do win fairly comfortably on emperor, take normally 16-20 hours on a standard map, could win on demi-god and possibly even deity but not prepared to spend 50+ hours on a game mm ing every thing, maybe one day
you have tiles worked by citizens that haven't been improved so you could gain more growth, trade and production if the workers are sent to the right places, 25 workers for 25-30 cities, i would have a few more at this stage, the extra work they fdo in the right place will probably pay for them
i see that you don't have a single barracks and therefore any productive military cities that can pump out vet units for the other cities without barracks, also you couldn't upgrade in an emergency (aren't they also militaristic? so cheaper barracks anyway)
you are doing your own research at quite a high level 80%? and pursuing a tech that the AI will go for, invention, i think sooner or later the AI may step ahead unless you're really careful with the trading and which techs to research, in my last emperor game i kept up by trying to research the unnecessary/unusual techs to trade for the usual at a lower rate, however you are the tech leader so you are doing something right, later i went communism and stole them all
i'll leave the rest to the better players than myself
however all in all very winnable imo
edit on looking at the save from my last game that was the closest to yours 110BC was mine, at that stage I had less cities, less workers, i actually probably didn't need so many barracks as i had built and so i should take note of my own advice, however i was stuck with alot of jungle / marshland and was constantly warring against a neighbour for their jungle/desert territory (almost certainly gives coal / oil etc later), i had no culture and subsequently lost 2 cities during my game
so your game is very winnable indeed i would say
i launched the ss in around 1700 with all other civs having built 9 parts (sounds close but i was stealing the tech and immediately selling it to everyone with ICBM prebuilds for the final part)