The cities aren't going to pop from people starving. They're going to pop because there's lot of Econ Expansion - available useful land. It means the countryside is full of attractive opportunities. All we need is to Expand Econ a few times -
next turn, give the incomparable military genius just one more turn - and people will come flooding back.
It's true that every plan will spend all 4 of our Econ. Can't avoid that, no matter what policy we use. We have to build the Dam, or it will trigger devastating Stability loss. We have to build the annex, because the patricians will hijack actions to make it happen. So that's all 4 Econ - regardless of what else we do. All we can control is how much Econ we recover later.
@Sivantic's plan recovers 14 + overflow, I believe, which should raise it to something like 25. That's enough to easily survive the turn.
We have a military genius like never before seen, we have levies already in the field, we have a really genuinely important CB, we will never get a better chance to stop the HK shenanigans for good.