Looks like an unloseable position. Set your research to 100% and you'll find you are at the top spot in GNP, production, crop yield, soldiers and population. The stack that shows when you open the save file is a little too wimpy to attack Japan judging by what's in Yokohama, but goodness me do you have lots more stuff everywhere else. Why are you even afraid of being attacked? Also, you have a Great Merchant about to give you 1100 gold to fuel whatever research you need.
However, there are a number of mistakes visible:
- You're not in Bureaucracy. Vassalage is useless. You're also not using any of the Religion civics.
- You are way behind in tech for where you are supposed to be at this time. It's hard to tell how this happened since your current situation looks reasonable enough.
- The way Athens is placed, you'll never be able to work the clams to the west of it. That may be a somewhat unavoidable result of settling in place without full visibility of the surroundings however (if so, this is not a criticism of your play, but of the map generator).
- Thebes has a similar problem (creating an unworkable fish). It probably needed to be founded on the rice (the fish tile is better than the rice tile).
- In any case, you should have had a workboat for the fish near Thebes a long time ago.
- In general, your cities seem too spaced out. Overlap is often good and helpful. You have very good land, and you're not even using all of it - there's an iron tile going to waste outside all your city borders.
- Many cities are either unhappy, or working unimproved tiles, or both. You need to be in slavery to whip away population that isn't useful to you. You probably also needed more workers to improve more of the land.
- Corinth is also working useless windmills rather than its cottages. Honestly I'd rather have mines on those hills.
- You're building grocers and markets, which are mostly useless to you. Whip away the unhealthy/unhappy population. Rather than grocers, build forges in cities that don't have them.
- New cities like Thebes (or Argos) shouldn't be building their own defensive units, especially if you have huge stacks of idle units lying around elsewhere. In a new city, focus on getting essential infrastructure (granaries...) up immediately. Workboats for both of these cities could have been built out of Athens to get them out faster.
- A minor thing, but I wouldn't promote Macemen with Charge.
My next steps here are to switch to Bureaucracy, Organized Religion, Slavery. That takes two turns, meanwhile arrange troops into two huge stacks placed so as to be able to reach Yokohama and Satsuma as quickly as possible. Some of the defensive units in Utrecht (one longbow and some archers) get moved to Amsterdam. Some other units are shuffled so that no city is empty. Once out of Anarchy, switch Athens to a workboat, Thebes and Corinth to a forge (which we'll whip), Nidaros to a settler (which we'll whip). Some workers are instructed to replace windmills with mines. Other workers start to provide irrigation to dry farms. Argos whips the workboat, switches to Granary.
I get to capture two Japanese cities quickly. Due to not paying enough attention I get a bit of a counterattack at Etruscan, but nothing I can't handle with the units that I held back (and some Knights and Horse Archers that move back once Yokohama and Satsuma no longer slow them down with Japanese culture). I obtain Paper (and Aesthetics), through trade and spying, and start researching Education and later Liberalism. Should later also get Literature, and build the National Epic in Nidaros (due to all the food) and the Heroic Epic perhaps in Corinth (what with those hills that could be mined).
In cities that have nothing better to do I build a few Buddhist missionaries to spread our religion to cities that don't have it yet, for the Organized Religion bonus.
I'm the first to Liberalism in 1750, and the Japanese capitulate in 1765 after I take all their cities on my continent, despite some annoying sloppiness-induced late setbacks (and Montezuma and Sury, who'd also declared on Tokugawa, nearly beat me to the last city). Meanwhile I've founded five cities in your original territory. Sadly Sury is first to Economics.
Try to achieve a similar result from your save.
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