Your mother may also be able to advocate for you, especially if your father continues to do nothing. I would recommend speaking to her and letting her know that this is more than just an annoyance, but that it's really affecting your experience during your visit with your Dad. Ask her to talk to your father or maybe both him and his new wife.

In the meantime, don't be afraid to reach out to your school counselor to help you deal with the stress of the situation, the divorce and your abusive step-brothers.