Behold the Korath! Evii Plays Galactic Civilizations II: Twilight of the Arnor
It seems that you may not understand one key different in the economy of this game compared to other civ likes. Production costs you money. Every single point of production an industrial building produces, or point of research a research building produces costs you 1 bc. That's why when you built that production building on the 700% bonus space, you suddenly started running a deficit. It's sometimes a good idea not to build production buildings until you get enough of a population to produce the money to support it.