Hello Natii and welcome to the multicultural experiences forum.
This situation you are experiencing is a difficult one and very common not only amongst cross-cultural couples but also with couples of the same culture.
When we create our own family, we become one with our partner, our 'other half'. No matter how much we love our parents, they're not our immediate family anymore. I understand that in certain cultures the boundaries are not as clear cut and the separation from the parents doesn't always take place, however, you could have been married to a Chinese husband who would still dislike your parents and/or set rules in his house that your parents wouldn't like.
Maybe give some credit to your husband for putting up with this difficult situation as he's clearly not coping very well with all this. Even if he knew that's the deal, as you say, it can be a very different story talking about it and 'know' that this may happen one day, to actually going through it on a daily basis and living it, knowing that this will probably continue for the rest of their days which could be for years. That can be a very depressing prospect for your partner who may be missing his life with you and the way things used to be between you.
People get tired. Living on top of each other or in each other's pockets brings conflict. It can be suffocating for the life of the couple and you have a new family to consider. Also, he is not used to this arrangements like you are.
It is admirable that you feel obliged to support and help your parents and you are so dedicated to them but I believe your affection and allegiance should be towards your husband first, the father of your child. Just remind yourself why you married him in the first place. Why you didn't stay with your parents instead, for the rest of your life.
Of course it's nice also that your parents have helped you out financially but at what cost? And having a newborn baby is one of the most stressful time in a couple's life as dynamics change, intimacy suffers, the couple hardly has any energy left to enjoy each other, the realization that the honeymoon is over can be daunting and some men especially may not be able to cope as well as a woman who has carried and given birth to her child. So, there are so many things to consider.
I'd suggest you and your husband talk to a Family Counsellor and your parents could talk to Seniors Rights to develop some strategies for your cohabitation. Family mediation can also help.