Yep, always my first thought. If you're in the US you can get tax benefits by making your home more energy efficient. It's doable yourself but hiring someone to do it will eventually pay for itself.

And for the attic don't just pile on insulation, need a good air sealing first if that's no good.

This. Lack of insulation, leaky doors and windows, etc. will give your system a lot of load. My sister has no insulation and her electric bill in the summer is double mine, and I live in a bigger house.