The Art of War - Defending a Rush

What on earth am I supposed to do here? I’ve got no resources to build more villagers or military units and the red guys just KEEP COMING AND COMING.

What am I missing here?

I’ve tried garrisoning some units and that seems to keep them alive but then my economy stops and MORE RED GUYS SHOW UP.

Is this whole game like this?

Hello, if you’re stuck just watch some videos:

You need to close the gaps to the south of your base. Build walls, houses etc to do so. On youtube there are some tutorials how to do the art of war scenarios if you have further trouble