I am in a catch 22 situation.?

I have a brother that my mother lives with, she sold her house, and used all her money to build an apartment attached to my brother's house. My mother starts trouble and then act as if she did nothing. I always lived close to her, I now live out of the country, and my brother is now realizing what she is really like. But now he is going along with her and her trouble making ways. She has tried to start rumors about my brother which I heard through a close friend and I ended that rumor quickly, and informed my brother, hoping that when she starts rumors about myself and my family, he ends it instead of feeding on it. I now am going to visit in a month and I told my mother, I would not step foot in my brother's house (which he makes it clear once the addition was built that it was his house). So I asked her to meet me somewhere and then I am going to take her to her summer house, which she never gets to go(she gets there only when I take her). My husband feels that we did nothing wrong and just hold my head high, and pick her up...but I also feel that my husband is only saying that for my sake. The last I talked to my mom she said I know you have to side with your husband, and I replied, no I am siding with who is right. I don't know what to do...I feel trapped.