Nothing wrong ..if he sends legal notice...he is not sending Al-Quida terrorists to you.
If you dont want to go to them...just say that they are not taking care of you and your baby and in laws are using abusive language. For that..you shud have some evidence to back your defences.
But pls...dont do recording and all and become a unskilled CID and spoil your marital life.
Gently, tell during counselling that you intend to continue with the marriage, but you need respect and care..which is not happening there with you. If your husband is not willing to stay seperate..then there can be a reason that his family needs his support financially. So dont press on that issue.
Your kid is managable now...8 months right. Take up a job for youself. And dont get into legal tangles. Girl you are facing teething trouble nothing more. Its very common with every girl. Things will change with time. If you start working then, you will forget such domestic issues and have a peaceful life ahead.