I'm so sorry to hear what you are going through. Mothers come in all forms. The emotionally abusive mothers sometimes were emotionally abused themselves and have low self-esteem. They feel competitive with their daughters and find ways of bringing them down.
In some cases, the mothers don't mean to be abusive and don't recognize their actions and words as being abusive. They are tying to "mold" their daughters into their idea of a perfect daughter, perhaps trying to get their daughters to live a life they themselves were incapable of achieving.
Sometimes, the mother sees all of her own defects in her daughter and that bothers her. So she attacks them.
Whatever the reason (and there could be many), you should not fall prey to those unhealthy beliefs. You MUST MUST MUST be strong and KNOW YOU ARE NOT THE ONE WITH THE PROBLEM. Keep your self esteem in tact and it will be hard if you've only heard negative feedback throughout your life.
It would be better to bunk with a friend than stay with this abusive person. But, if you must stay...
Try to tap into her good mother side. Open dialogue and apologize for any hurts you may have caused her. Be the little girl again and hug her and tell her you're sorry. A lot of the problem is that mothers have a hard time adjusting to their little girls growing up into their own womanhood. My dad always said it was impossible for two grown women to live under the same roof. That is why teenage girls and their moms begin to have problems. Partly too, it is a way for them to separate more easily when it is time.
But try to rekindle the mother-daughter bond while you're there. If she has any amount of good mothering sense in her, she'll melt.
If this is impossible, keep your head low, do your share of the household chores, if you work buy her little gifts she'll like whether it is her favorite ice cream or perfume or flowers, etc. In other words, kiss her rear so she'll keep off your back!
Do NOT attempt to go head to head with her in arguments. Don't start them and don't get involved in them. Learn the important lesson of biting your tongue.
Then, go to college as a free and healthy person! Remember above all else that YOU define yourself. YOU make yourself into whatever you want. ALL the horrible things she said about you proves how low she thinks of herself and what type of heart she has.
BE YOU AND THRIVE!
