Is it hard to get emancipated?

I am in a pickle. I live with my boyfriend who is 20 and i am 17 in Arizona. Nobody has custody of me and i am trying to figure out what to do because my dad is threatening to get custody of me and sue my boyfriend. so i am considering and weighing a few options. please help me. i thought about marrying him since nobody has custody of me and my mom loves him but she lives in alabama and she couold sign to let me marry him, she suggested it. or i could get emanicapated so that my dad has no way of getting custody of me just to get my boyfreind in trouble. My dad said he doesn't care where i live as long as it is not with my boyfreind. he is simply stirring up problems just for the heck of it.