Is it possible to get a new roommate? That would be a big help. Or your crazy landlord now having issue with it?
I don’t know about your mom but I wonder if when she suggested helping you, she didn’t ask what would be the amount of monthly help. She probably thought with a roommate it would be a couple of hundreds a month. But you said it is 2.5k a month (unless I read it wrong), and that’s just not affordable for anyone. I wonder if that’s why she is backing out. Not from helping you but from giving such high amount.
Hoping for it to be resolved with a roommate!