The problem was that I couldn't raise the tax rate or I'd be making even more money. And I couldn't lower the tax rate since I had already hit pop max for most colonies.
Eventually I decided on spamming industrial plants and constructors.
Even still, the situation is now 40,000 in the bank. Thankfully I'm finally running a deficit, though my approval rate is still catastrophically high.
I'm afraid of raising taxes because then I would have even more money. I don't want to build units because it would be too much to manage (I have 50 or so planets all through expansion or influence switch and control half the galaxy). so instead I'm just building starbases.
I have yet to build a single military unit other than constructors, colony ships, miners and freighters. The Drenin are still desperately trying to destroy one of my dozen or so heavily fortified economic/influence starbases. I watch their starships move into the starbase and blow up while I sit and laugh . Maybe it's time to move onto the next difficulty level.