Dad fighting Son?

My dad is 39 years old and he says next time i screw up he says he is gonna kick my azz. im 15 years old i think he is a little crazy. can he do that? he says if i call the cops hes gonna tear me apart when he gets out. he is a psyco. he used 2 deal drugs and hits me and my mom before she divorced him. the judge gave him custody over me. please tell me what i can do about him.