MOMSTER IN LAW

So my fiancés mom & I were going good in the beginning then suddenly she started to hate me . She hates when he does anything for me, HATES that he pays my bills and claims I “take all his money” because I am 100% financially supported by him while having my own income. Suddenly she banned me from her house which i don’t give a f*ck . She LAUGHED when I miscarried her grandchild days before mothers days & was upset that my fiancé celebrated me with gifts claiming “she’s not a mom” “I’m your mom my gift should have been more expensive & bigger” “the baby died , she doesn’t count as a mom” fast forward she banned him from her house and talk bad about him throughout the family as well . Claim she hates him, yes her own son ! So he’s due for a really larger amount of money due to an accident he got into & now she wants to cook him a meal and invite him over to make up . I feel fishy about it but she’s so sweet and forgiving he’s telling me I’m over reacting. I’m just so protective of him and to have to protect him from his own mom is sickening but I don’t believe it’s from her heart , thoughts ???