My house is always cold.
My heater furnace is gas, with radiators in my old house. It is never warm and the heat is so uneven. I keep my thermostat on 68 degrees most of the time, but on colder days, I turned it to 70 degrees. My radiators seem to get hot during the mid morning. I have 4 bedrooms and two of them I have to use electric heaters.
Wow, from what you are describing it sounds like you have a leaky home.
I would recommend you have a blower door and duct test completed by a building/ home energy rater. They are the best at finding the leaks and recommending ways to seal your home in an effort to increase comfort and save energy/ gas at the same time. Make sure they are certified with either BPI or RESNET and are listed.
You might also want to contact your power company and ask if they have any FREE programs to help seal your home and make it more efficient.
Hope this helps.