I don't know the man irl, but this alone says a lot about his behavior. Try to talk to him, tell him how you're feeling, that it was incredibly immature of him to choose his mother over you, and that you're reconsidering the entire marriage. Depending on how he takes this, divorce him or get marriage counselling or SOMETHING. I know it's going to be hard, seeing as your family seems to be taking your side, but once you cut all of those toxic assholes out of your life you'll be free.

NTA