You need to think clearly about the relationship you have with your mother in law. I agree that some relationships are toxic, and best avoided, but before you do anything you might regret later, think about what she means to you. What is your relationship like apart from this? She may actually have your welfare at heart, but is projecting it badly. She may be a lot of help to you at times, but it needs to be on your terms, not hers. All the best.