guys what do i do?

I turn 18 in 7 months and I've got a long distance partner who I am planning to live with soon. my father has forbade it and my stepmom and him keep being absolute assholes about me wanting my freedom. They took my phone and threw away the sim card and i lose my laptop before i graduate high school in may. I am getting desperate and my parents are getting more brutal. They do not approve of the fact I am trans (ftm) and keep making backwards comments and trying to "force me back into the closet". I need a phone so I can talk to my partner and start doing stuff for work but my stepmom won't give it back or get me a new one or let me get a job. My dad won't stand up for either so I'm pretty alone. I need advice. What do I do?