Oh hun, I don't know what to say. As embarrassing as it would be to have your private life on display in your professional arena, it might still be worth it to get some peace from them. You'd have to be prepared to laugh it off at work with a "don't you wish YOU could get an AVO on your mother-in-law!" or "aren't all in-laws bonkers?" kind of attitude.
Other than that,move away...far, far away!