I'm so sorry to hear your mother and sister have bodyshamed you No one, NO ONE should do that to others (or themselves)!

If your mother is the kind of person you can actually talk to, I would tell her you know her opinion on the matter, but it's your body and you decide what to do with it - and can she please stop talking about the subject because it's making you feel bad and is not helping you in any way.

I understand you're feeling angry about this, but I've found it's best to try and talk to people when you're calm - if your mother feels like you're attacking her, she might get defensive and you could end up in a shouting match where nothing gets solved.

I also think Trippin makes a good point about your mum maybe wanting to help you, but she could be going the wrong way about it, and ultimately, what matters is how you feel about how she treats you. You have every right to set boundaries and people should respect them - sadly, some never will in which case I think it's best to try and keep away from them as much as you can..

As a long-term plan, I would start to learn ways of coping so that you can eventually move out. I know it's hard to trust others when you've been treated badly, but not everyone is like the ones who have wronged you. I have HUGE trust issues but have found that once I pluck up the courage to ask for help, people are generally quite nice and happy to help if they can. Good people aren't going to think you're stupid or weak - it's normal to need help, and healthy to not want to do everything on your own!

I really hope things get better for you - hang in there! All the best