If you own your house CU does have a program where they can check for leaks around your windows and doors. I'm not sure if you have to qualify income wise or if it is available to everyone. They will also do it for renters but need landlord approval. They also have a program to insulate homes for lower income people.

As far as things you can do on your own, make sure your windows have a good seal of caulk around them, use fans (pointed at the ceiling) or ceiling fans (in reverse or winter mode) to bring the warm air away from the ceiling and towards the floor, and get a programmable thermostat that can automatically adjust for different times of the day. When awake have it set a little warmer and when away or asleep have it set cooler.