Any other ladies here not get along with their mother-in-law/future mother-in-law? It's starting to…

Any other ladies here not get along with their mother-in-law/future mother-in-law? It's starting to become an issue between my boyfriend and I because I can't stand his mother. I try and try and finally last night I've had enough. I'm done playing nice. I told her this morning that if she wants to act like a child that, that is fine and we can only communicate about my son from now on. There's many reasons I do not like this woman but the main one is that she treats my child like he's hers and doubts my ability to care for him. I cannot stand that. I am a great mother and I know that! #EndOfRant lol