Mother-in-law Hell

ok here goes please excuse the improper punctuation i’m just gonna let it flow…my fiance and i have been together for 4 years and his mother is just a b**** from hell has hated me from day one always making snide remarks and backhanded comments about me the worst part is that she and the x are bf the x cheated on my fiance with a man for 2+ years then married him weeks after her divorce yet in mil eyes she can do no wrong when i confront fiance about these issues he says just ignore her that his mom has always been that way and that he just lets it roll off his back well i can’t you see she always says that she is the type to say what she thinks problem is most of her true feelings aren’t told to me but to the x she has even gone as far as to call me high and mighty please whatever anyone who knows me knows that i am one of the most down to earth people there is but unlike mil i am honest so if she ever asks me a question i give a direct to her face honest answer which she then takes back to the x and says that i said _ instead that she asked and my answer was _ she has been telling anyone that would listen that we will never last and it just goes on and on she doesn’t even know me she never gave me a chance she’s so stuck on wanting fiance back with cheating homewrecking whore of an x wife that she can’t see past it at times i feel i’m ready to just walk away it’s too exhausting although i love my fiance dearly i sometimes feel that i try so hard mostly out of spite for his b**** of a mother……………HELP