My mother and cat

I was on the phone with my brother for four hours and I told him about my triggers and I just opened up about it and it was really nice to talk to somebody but then I get off the phone and my mother who I’m staying with right now is randomly putting one of the cats down for no reason other than she’s afraid of being kicked out which I get that, but I don’t know how to deal with this besides pretend like I don’t care when I feel terrible like this is my fault .. I just don’t like this sort of thing and it feels cold and I hate having to witness it