This is long, but I really need help. Was I in the wrong or was she?

A HUGE THANK YOU TO ANYONE WHO READS THIS AND ANSWERS SERIOUSLY!!! Okay, well first off I'm 14. I know I'm young but I've been through a lot so I guess it makes me a little more mature. I've come to accept the fact that my mom is emotionally, and sometimes domestically abusive. I could tell you everything she's told me, but that'd take forever and make me more upset than I am right now. But to tell you a small list, she's called me immature, irresponsible, hateful, evil, a jerk, a horrible daughter and she's told me that she would sign my custody papers away (I'm not really sure what that means, but I know it means she would give me away) that she would kill herself if I didn't listen to her, that my brother is better than me, and even that she doesn't care about me. She gets mad at me over really stupid things. Like, twice, yes twice, she's gotten mad at me for something over Facebook, yes seriously. The first time it was like I embarred her or something, I honestly don't know, but she had me sobbing on the floor begging her to forgive me and saying I was sorry for something I didn't even know what I did. She said I was fake crying (something I can't do) and I wasn't sorry at all. She ended up taking my blanket on my bed and just saying I wasn't sorry. The second time, about a month or so ago, she got mad at me again for Facebook for something, which once again I don't know/ chose no to remember what it is, i stood up for myself this time. I told her that it was really immature, and it's just a website and means nothing. She ended up yelling at me and I stayed in my bedroom for the rest of the day/ night. She's shoved me, pushed me, and slapped me. But back to tonight, well I've had a bad day already, I was late for school, I didn't get much sleep last night, and I have this big singing competition coming up on thursday and friday. I've been staying up late studying and practicing for this competition, until about 3am sometimes. Well, to say the least I was exhausted when I got home. My mom was in a HORRIBLE mood. She was already yelling at my dad. My mom had to go to the doctor. My dad ran out of gas on the side of the road. He got gas and went to pick her up, and was late. I was at home watching my brother, I had sat down for a second and ended up ping out. Well, the next thing I know I was woken up to my mom yelling in my ear. Calling me irresponsible, untrustworthy, and a bad daughter. I said I was sorry for falling asleep, and she said I was being smart. My dad said it was his fault but she ignored him and kept yelling at me. She told me to get my a** out of bed and clean my room. Well, through sobbing I cleaned my room. I just want to know, was I wrong? Why does she hate me? Why does she yell at me? What did I do? Does she like seeing me sad? I've been crying since she yelled at me and I can't stop crying. Please someone help. Watch no one answer this....