@DashDynamic,
Dash,
You can't change your family, you are born into it but you sure as heck can leave the roost when that day comes and never look back.
Concentrate on what you are contemplating, not pulling faces or answering back because you are going to need to have that skill in the outside World, when you get a job and you are going to need that skill when you meet a guy that you want to go out with, you don't want to be like her and often what we are used to is how we become.
You're mother is a bully it doesn't matter if she targets you more than your brother, she is a bully. Verbal abuse, physical abuse, emotional abuse, look them all up, read up on it and understand it. I think that, that would be good for you, so that you see you are not playing victim it's real and you are a better person.
Just remember you are not like her and never will be. Can you perhaps get some free counselling? Thinking of dying to get away is not a good thing at all and sometimes as you have no-one to talk to, reaching out and discussing it with a Professional can really put things into perspective for you.
Study hard, get your grades up to the point you can obtain jobs that you like but, as soon as you are able, get a job whether you like it or not, be respectful to the Managers
And, earn the income you need to get your own little place somewhere.
There's a whole lot of happiness out there in this World and you will find it when the time is right.
Sorry you have had to go through all of this. Be strong from it.