You need insulation. Fill up the attic.

Then start caulking any crack on your exterior walls. If you have old windows, the seals are probably bad, so fix that. Cheap fix is to use window sheeting (plastic sheet that you put over windows and use a hair dryer to seal).

If you have a unfinished/open basement, your flooring could be letting that cool air in, so insulate. Pretty much seal any possible air gap on the exterior.

Then clean your air filters if you have HVAC. If it's just radiators, make sure they are working properly. Wear blankets and extra layers.
Ask Bge to come do an energy audit including finding out if you have a gas leak or electricity being used somewhere it shouldnt (including theft by neighbors).

Bge raised rates quite a bit this year for delivery, not supply. So yes it's expensive. If you are lower income or have periods of the year where you are lower income for a 30 day period, apply for energy assistance (OHEP). If you qualify Maryland has heating and electric grants to help pay bills. The average benefit is $500 per year. But there are many grants.

Links to OHEP: https://dhs.maryland.gov/office-of-home-energy-programs/

Application: https://mydhrbenefits.dhr.state.md.us/

Provide all documentation needed all at once with the application, Not separately. This will ensure the case is processed quickly and items not scattered.

If you have back water or sewer bills, also look at grants for that (can apply on same above page).

If you need to make major home repairs go here for grant funding: https://dhcd.maryland.gov/Residents/Pages/SpecialLoans.aspx

https://dhcd.maryland.gov/Residents/Pages/WholeHome.aspx

https://dhcd.baltimorecity.gov/hho/rehabilitation-and-repairs

https://marylandhaf.com/

https://dhcd.maryland.gov/Residents/Pages/HomeownerAssistanceFund.aspx