You may have to like you stated in order to protect your mental well-being. This environment has become toxic and unhealthy. It sounds like your wife is enmeshed with you MIL...that is not healthy.

You could try to get her or you into therapy or both go to one of your therapy session so your tdoc could kindly point out what's happening with you and how she can support you.

Something needs to change or you need to get out. Best wishes.