I suspect my mother in law is sabotaging my relationship with my husband. She's very two faced and likes to twist everything I say. But she's very nice in front of me. What should I do?

I suggest that you sit down with her. I know it is not always easy to blend in and please in-laws but you need to still put your extra effort just so your relationship could be better. Ask her, in the calmest and sincerest way possible, why is she acting that way. Ask her if there is something wrong that you did or what she doesn't like about you and what she thinks you should improve on. Raise the issue with your husband, too. He needs to know because he help you with all the advices you'll need on how to deal with your mother in law. Tell him that you are not happy about how she treats you but you are eager to put extra effort just to win your MIL's heart. Tell him how important keeping a good relationship with your in-laws is and that you really want to solve this dilemma.