Hi there Frenchie08. I read all your post and I'm really sorry for your situation... I believe it doesn't matter who you are, it would be hard not to be anxious or worried in a situation like that, so, first of all, congratulations for hanging in there.
Of course I've never been there where you are, but it seems like you're in the right track. I have the same tendency of protecting my mom and taking care of my brother since her and my father got divorced (and my father still is the best father in the world, just a little bit absent), so I can imagine your situation being 100 times worse.
But when I moved here to the US, I had to deal with something similar... like I was abandoning my family, being selfish or something... like I was needed there in order to everything happens the way it should.
But I wasn't.
Life goes on without us, everybody keeps on living. And even if we can make it better, one thing that I learned (or I'd say, struggle with) is that we cannot be necessary. What if you disappear in the air? Things would keep going without you.
There's nothing selfish about you trying to live your life in peace. And there's nothing wrong about you wanting to help your mom either... but, like you said, she brought it up on her. She could have said no to the officers, maybe she could have left your father first time he beated her... in reality, she could choose not to be the victim all the time.
And it's not fair that you go crazy because of her choices. (And maybe that's what your sisters think).
I'm sorry about anything I said, of course all I can have is the outside view, and I don't know the reasons your mom did what she did, but based on what you've written, you really need to detach yourself and look upon all that situation as an outsider. And live your life to the fullest... who's gonna be there to worry about you if anxiety takes the best of you? Or who gonna help your mom eventually, like you did about her medications?
Good luck. And hang on to the good things you have, your life, your family.