You should sit down and talk to her just you two alone and tell her the problems that you have. Have you said anything ? Because if you don't she will never know what the problem is . And maybe thats something yall need to get counseling for. Because both of yall hating each others mother cant be a healthy environment to raise children .
I am so sorry that you are in this position. I can understand how you feel. Before I got engaged my mother in law and I got a long I thought I was going to be lucky. When her son purposed everything changed. She hated me and did everything she good to break us up. She didn't respect boundaries and she destroyed my marriage. My husband didn't stand up for me and allowed her to destroy my marriage. We are now divorced and that wasn't my choice.
I would strongely encourage you to seek counseling together. I know of a place you can call for free licensed counselors that would love to help if your interested. This is a big deal and I am not in anyway saying you will end up like my marriage, but you need some help from a counselor.
Live, Laugh, and Cantor on
I'm in the exact same boat as you except my patience ran thin after being accuse do taking drugs and drinking alcohol while breastfeeding so I had, had enough and cut them off from me and son and my soon newborn son it's been 3 years and I've never been happier. My husband also cut them off seeing the way they treated me and that's basically how he was treated so of course it wad hard but they definitely made the decision a hell of alot easier especially after threats to take our baby from us and bla bbla sometimes your better off without poison in your life even if it is family.
I have a crazy sister so I've been through this my whole life. I'd say it depends on crazy how. Do they demand you do certain things or do they just say stuff that gets you uptight? I don't put up with demands. However, if you are a FTM or this is the first child you have had in their family, then most MIL and company just want to be helpful and pass along any tips they know. Sometimes they can be a valuable resource. But don't let them pressure you. Do your best to stay calm and tell them you appreciate their advice and consider it but that the decision is ultimately yours. Be firm but also be kind. Grandma's tend to feel left out if you don't consult them occasionally. Especially hormonal ones! If she is going through the change it may just be that she feels old and is trying to regain some youth by inserting herself this way. I really believe most of these issues can be resolved amicably. Granted, some people are outright wrong (possessive, demanding, rude).
I'm going through the same thing just that with me it's crazy MIL and insane sister in law. It's just way worse. I have to admit at times I wish they live in another state/ country/ planet if possible.