Have you checked your vents and do you know where they are? Newer houses have vents that vent to the outside of the house, which depending on the location can get covered with snow. Blocked vents can have Carbon Monoxide backing up into your home. If they're covered, go outside and shovel around them so they are clear. Check out this article here
Did your pipes freeze? At this point if they're frozen, you can attempt to unthaw them with things like a hair dryer or portable space heater. Keep your faucets open while your pipes are thawing so the water has somewhere to go. Once they're completely thawed, consider where the pipes that became frozen are. Maybe you can insulate them in the short term, and call someone to insulate them professionally when the weather gets better. If they've burst, call a professional plumber ASAP!
Does your home feel cold and drafty? When it feels negative 2 outside, you're not going to be going around outside your home caulking all the drafty areas you can find. You can use drapes and curtains to block the windows and keep the draft out. You can also insulate your drafty windows with bubble wrap. Check out how to install it here. This should get your through the winter until you can install some new windows.
Is your furnace not keeping up with the cold? You can call in a professional to service it, but with this extreme cold it will be costly. You can use a space heater for just your living space to help out your system until you can get it serviced/replaced. Using a fireplace safely can help you too. But only use it if you've had your chimney has been inspected and cleaned out, because a chimney fire can be hard to put out and will be devastating! Use caution!
I really wanted to get this out there because frankly, tips to keep your house warm are for things you should do to your home when the weather is nice! But if you didn't get a chance to do them, this extreme cold can be a wake up call for maintenance you need to get done. But in the meantime there's things you can do to minimize the chill! Stay Warm Annapolis!