No heat in the house for 1 month...Is the landlord responsible even if 2 months behind on rent?

I'm behind with Nov and Dec's rent mainly due to skyrocketing electric bills due nonworking furnace before it finally said "kaput" on Feb 9. My electric bills have been no less than $750 per month since November. I have Feb's rent and March's rent and haven't paid because I'm also looking at houses now that this issue has been ignored. I have a family of 4 children and live in Bel Air, MD. What are my best options--other than escrow. I would like to know if I can subtract cost of increased electric since d/t faulty furnace and purchase of space heaters, pain and suffering, etc...