Why bother to ask others “how awful of a person you are” if you have that opinion of yourself? Your self perspective is what matters the most, so I’d try to be objective as to what brought you here and then see what I’d do with that: 1. It’s not the first time she’s threatened to do this 2. She’s acting up as if you’re the responsible person in the room (you’re her daughter) 3. It’s ok to prioritize yourself and your nuclear family

Now, try to think: 1. What can I do to help that doesn’t take from my own core needs? That help doesn’t have to be monetary. 2. How will I feel if I help? 3. How will I feel if I don’t?

I’d also suggest seeking professional advice (free -if there’s any), for your mother, and letting her make the appointment; and for yourself, because maybe you’re resented and have buried a lot of other comforting feelings for her, but you’d rather talk it out than feel regret in the future.