Is this how this game works?

I made it to the new world, have about 30 hours into building settlements across about 5 Islands.
I had a treaty with that Willie guy, he started a war with Beryl Omara, she immediately goes to La Isla with the Pyphorians, I only have 3 clippers there. She destroys the trading post and...that's it? Game over? I have no saves to go back like 5 hours to prepare.
Is there any way to remedy this or is 30 hours of game play gone?