I have had to walk away from abusive family before. My grandpa. Fortunately, it didn't last forever - when he realized I was serious, he shaped up, at least around me. It was the hardest thing ever for me because my grandma means the world to me. But I reached a point where I knew I had to do it, for my own health, so that I could be the best person I could be. I was starting to grow hateful, and that wasn't the type of person I wanted to become.
I can't watch your video, knowing that it will hit me way too close to home, but take my word for it - since you are not dependent on your family, consider yourself lucky and try to make some breaks. You don't even have to tell your mother you are "done", just take the break and don't do anything final. You can't grow into who you want to be when you are surrounded with people who are abusive towards you. You have to be emotionally healthy, not just for you, but for the people who love and care about you.