I want to first applaud you for reaching out for help. I am sure there are a lot more details to your situation than you have written.
I am suggesting that you come to some understanding (clear) of what you want moving forward from your husband and write them down (take time and really gather your thoughts). It is important that you communicate that with your husband and allow for an open (respectful) conversation with your husband as to what he wants moving forward as well.
You are very young, I am not at all saying you should get a divorce, but being mentally and physically tortured is not healthy for you or your child and honestly I cannot whole heartedly tell you to remain in a situation where you are losing yourself (emotionally/mentally).
Marriage is very challenging in itself but when extended family play a huge role it could be even more frustrating. Are you aware or do you have an idea why his family is that way towards you? Have you reached out to your husband about the situation? Have they always been like this or did a recent event change this relationship?
Is he open to therapy for you all to work out these issues. It sounds like you may need to ask if marriage is what your husband wants as well? or if he still loves you? Its tough questions, but sometimes we need to be realistic about what we see at face value.
So many questions, but I cant concretely give you advice without some dialogue.
Hope some of these questions peek suggestions for you moving forward.