my mother

My whole life my mother has put me down. theres a side of her that is lovely but the other side where she is insecure, mean and never happy. we are very different in some aspects. she doesnt agree with certain things I do. for example my wedding. we opted for a cheap small celebration and she had to pick on so many things but in actual fact everyone had the best time. shes forever criticizing me and my choices. im 28 married with a child and another on the way. i want to cut her off but i dont at the same time but i cant continue to get upset everything i speak to her. shes not someone that i can just tell her how i feel without me being the bad person. what can i do about this?