You need to talk with him and communicate your feelings about how his family makes you feel... another thing you need to do is move out... your living in a toxic environment and that stress is not good for you or your baby... if he really loves you and cares... he wont put up with his families crap
Have you told him how you feel about the way his family treats you? Me and my husband use to live in cali by my family and when he decided to get out of the military and move to texas where hes from and near his family at this point we were married 3 years his family treated me like **** and it took him awhile but after i complained to him enough and he saw the way they treated he spoke up after he stuck up for me they started treating me better and stopped talking **** behind my back. If he stands up for you and they stop then that would be great or maybe you guys can get a place with just the 2 of you. Me and my husband have been married 5 years now it gets easier.
You have to do what's best for you and your baby. Maybe you and him could get your own place together its always stressful living with in-laws. But only stay with someone if that's what you really want and what makes you happy. Goodluck.