It's pretty drastic to call yourself "a bad person" for one angry thought.
It's not good to give in to anger like that. You start to dwell on daydreams about people burning to death, and you'll just end up getting angrier and angrier until it takes over your life. So, it's a bad idea. But I think your conscience is telling you that already.
Anger, by itself, is justified, though. Your landlord is upset that your assistance program will be late in January. She must be aware that this is not something you can change, and yet she seems to have taken her annoyance out on you. Many people don't understand what it is like to depend on an assistance program for your housing, and they don't understand that we would really rather be working. They have never considered what it would be like for them if they were to become ill or injured enough to become unable to work and need housing assistance themselves.
Is this going to be a one-time thing? You could borrow the money to pay your landlord, if you can get the loan, so that there won't be a late fee. Then when the money comes in, in January, you can pay the loan back.
Sometimes I think the best way to deal with people like this, is to prove yourself to be a whole lot nicer and generally more decent than they are. She doesn't like your late payment? Fine. That's her problem; don't let her force you into hating her. If you can manage to get the money in on time, via a loan from a friend, then maybe she'll feel ashamed about taking it out on you so harshly. Or maybe she'll feel smug about making the welfare bum pay up, in which case she'll show her true bigoted colors even more strongly than she has been.
But however she reacts, this is not your fault. You didn't do anything to cause this; the payment will come in, even if it is going to be late. You even notified her. You can't be expected to do any more than that. Daydreaming about fatal house fires is not going to make you feel any better.