annoying parents

Why are my parents so dependent on me. I'm 18 and my dad always tries to force me to go with my mom everywhere. Then when I say no because I'm tired of getting bossed around he bitches all the time. Like if she has to go to my 13 year old brothers school, to go see my other younger brother in juvenile or even the stores. He's always bugging me about "oh you need to go with your mom." I'm getting frustrated of them always depending on me. I been doing it all my life and I'm already at the age that I no longer give a fuck. I know I probably seen rude or selfish but all my life it's been this way. Like I already have a bf and my dad is always saying "oh you always wanna go with him". Well no duh I'm older already I don't wanna always be in one room especially since we live in a hotel. It's so annoying it's already bad enough he won't let me move out. He says he wants me to have my own place before I leave. I'm 18 and tired of all this bullshit. My bf gets mad because he's saying that it's messed up that I listen to them all the time because they scare me and he knows they'll bitch if I don't. I have brothers and they never ask them to go with her it's like they are so dependent of me. A job here where i stay isn't gonna help me get my own place.i already have somewhere to stay he just won't let me go. He said he'll go to the house I live and will start shit. I won't regret anything since my dad is nothing but a drunk and druggy and I'm tired of getting bossed around.