Why do we argue all the time?

Me and my family (Mum, Dad and brother) argue pretty much everyday, somethings it's little pathetic arguments where as others are big ones. It's really getting to me, I'm 18 years old and I really do not need all this. My Mum gets really nasty, and I mean really nasty. She blames everything on me, and when I try to confront her she just has another huge blow at me. I kind of try to talk to her about it, and my Dad but it doesn't work, we still argue. I talk to my friends, they tell me to ignore her, have words with her etc but none of it works. I sometimes really wish I was brought up by different people, I get upset constantly, I've started to gain weight because I'm getting upset and taking my moods out on the food cupboard. I seriously do not want this life, and I know most of you are probably going to think I'm being melodramatic but seriously, if you came home to arguments every single day you'd feel just how I feel. My Mum pretty much makes all my decisions for me, she doesn't allow me to do certain things, and makes me do others. One day, I'm definitely leaving and going to live somewhere else. I don't know what to do, recently I've just been keeping my self to my self in my bedroom, drawing, writing, etc before I go back to college in September.. I just want some advice, I seriously don't know what to do :(