Uh... yow. Without A/C I'm running 380 kWh a month. My parents use several times that, but they have an enormous house (it has its own ballroom) and they make no attempt at all to be energy-efficient.
Have you considered LED lighting? It saved a lot more energy than I expected.
Of course it sounds like the A/C is the dominant expense where you are, and even with really good insulation, even good heat pumps are pretty expensive to run. My A/C has been known to triple my electric bill.