Can someone please tell me what to do it's an emergency

My dad just beat me with a cable cord because i tried leaving the house with a couple of my things. I turn 18 in a month, so i'm allowed to leave according to the law. I'm leaving because they've basically told me every single day for the past month on how i should leave, this morning i woke up to my mother screaming at me saying i'm a waste of space in her house. My boyfriend who is already 18 is renting his own place and he said he will gladly take me in, so that's what i was gonna do and also get a job to support myself. What should i do? my dads keeping me locked in my room, after beating me and stood overtop of me for 15 minuets to make sure i didn't take pictures of what he did or call the police on him. He popped a vein in my knuckle. here are some pictures.
Side note: he's sitting by the door so i won't attempt to leave again.