My life is going downhill?

Ok, so before I get put down and called a moody teenager, I just want to make it clear thats not my problem.

Earlier this school year (I'm a senior) my "friend" (a term I've learned to use loosely) randomly decided to send me a text declaring the end of our friendship. It doesn't end there though. All of the people we were friends with is siding with her (she"s very manipulative) leaving me friendless. I'm a very opinionated and blunt person, I refuse to censor myself because I feel thats fake. Up until my "friend" ended the friendship, my personality was funny, admirable and refreshing. Now since she doesn't like me, she's got this theory that I'm mean and sour. Its a well known fact that I'm defensive of my friends and I'm a generous person, but I'm not afraid to curse somebody out if necessary. She wants people to think I'm a bad person. (she became friends with this girl that hates me. this girl is willing to do whatever to get her way)

Next, my home life sucks. My brother abandoned us (I say this because him and I were super close), my dad is terrible to me (he's physically and mentally abusive, narcissistic and controlling), and I feel betrayed by my mom for not leaving him years ago. I feel as though my parents don't care about anything but my grades. They never asks how I feel, but what my grades are like. My dad (it even kills me to call him that) is the worse. He talks down on me, he's put his hands on me too many times, and he never apologizes or says I love you. When he punched me in my face, instead of apologizing and making me feel loved, he buys me an iPhone. I'm sick of them showering me with material things instead of making me feel worthy. The fact that my mom doesn't defend me or divorce him breaks my heart. She wants me to have a father figure, but her "father figure" is driving me insane.

I've been broken and torn down, I cannot take it. My once confident, outgoing and blunt personality is now reserved, sad and nonexistent. I feel so unmotivated about everything. I have made a few new friends with ease, but its not the same. I've been close with those girls for so many years, but the fact that they've all ganged up on me is too much for me to handle, mostly because we haven't had a falling out, but the ex friend's actions cause a split that isolated me. When she's not around Im their friend, and I don't do sometime-y friends, so I've decided not to call them my friends.

Any input on how I should deal? I really don't want to be bothered with this childish sh*t since I'm 18 now, but I know ignoring it won't make the problem go away.