Legal divorce from parents?

im 18 and i have not lived wit my parents in 2 years my mother is a druggie and my dad is verbally abusive..talking down on me anytime he gets..im sure he loves me sum where anyone he does pay my insurance and that only which he will be talkin me off by the end of this year and he will not give me a penny..so how do i prove to fafsa that i am independent..other then bein a teen wife/mother?