Advice?

Hi! So I have some issues that I kind of want to see if anyone has advice for. Let me start this off by saying I’m developing an eating disorder. My mother is an alcoholic and spends more money on alcohol in the house than she actually goes out and does grocery shopping (even then it’s normally munchies). I lost 20 pounds in roughly 4 months from not eating or eating once a day while living with her. I currently live with my BF’s family and they eat nothing but starches, steak, sweets, and junk food. Which don’t get me wrong I enjoy meat in proportions but not every night for dinner. There’s no variety. And as far as junk food goes I have to watch out for diabetes (runs in the family) so I try to eat pretty healthy. Well since I don’t have the power to do that and my bf’s mother doesn’t want to shop healthily (she has lupus so she should...but I digress) I have only been eating once a day, if not once every couple of days (now I’m just not hungry anymore, like my body craves something but I just don’t want what is served at their home). I was 140 pounds in June and I’m now 125. I’m on the verge of being underweight and I’ve *complained* (expressed my concerns for my health) multiple times on seemingly deaf ears. Has anyone been in a similar situation? Or have any advice as to what I can maybe do?