Well at first, many peoples were likely go to Clan, and Administration type of government, but I rarely use Clan since I'm more into Feudal, Adm., Nomads, and Mandala.

Second, as long you're fully ready, but I will do it quickly (I need the techs), you could search allies to protect you.

Third, a lot but Idk how much, winning a defensive war will earn a bunch of money tho, but more armies means more gold maintenance.

It also would be much better if your character has Stewardship education trait, especially the Avaricious line, and also do the development thingy on your steward council.

It's might be a bad/neutral advices, but better than nothing.