J.F.
You mentioned you live in a trailer.....that's the reason your bill is so high. No matter how new it may be, mobile homes are not built with hardly any insulation. I lived in one and in the winter the walls would ice over on the inside!
My mom (yes, my mom) framed in the inside of the walls, installed insulation, and then new drywall over that. She also insulated the ceiling and reroofed the trailer. It made ALL THE DIFFERENCE.
Look at what you can do to improve the insulation and windows and doors(most windows in trailers are only single paned and metal). It may be worth spending the money up front to save on the heat bills.
GOOD LUCK!