OP I remember your previous threads.
And I am sorry, I am really really sorry that you don't have the respectful, supportive in law relationship you deserve, that your husband doesn't have the loving, accepting parental relationship he deserves and your child (and potential future children) doesn't have the loving, accepting, supportive relationship with their grandparents they deserve.
And I am sorry that their behaviour may be causing a strain on your marriage as you grapple with being scapegoated while your husband struggles to re-evaluate his relationship with his parents, which even if he is emotionally mature enough to deal with appropriately, will be painful.
It's rough, and you need to make some time to grieve it, while supporting your husband to grieve this loss to.
I am also sorry that your in laws have chosen to be so batshit. It is very hard to get appropriate support in RL when you have in laws who are being awful in odd ways. It is quite taboo to criticise in laws and other parental figures for doing anything less than physically abusing you in RL, and it is a real burden to bear.
Just to give you some examples, I have been accused of being responsible for big, bad family rows with the ILs for the following:
Accepting a lift from my mother
Not liking cats
Being cross with DH that he hadn't sorted out train tickets for a trip
That is a minor selection, but I hope it will illustrate the point that it really doesn't matter what you do, they will always find something.
They have very conviniently found an excuse to behave badly, that they can blame you for. It is very important neither you nor your husband accept the blame for this.
Have you considered couples counselling, more aimed at helping your DH deal with the situation and learn how to deal with his rejection by his parents in a constructive way.
It sounds like you have tried low contact, it hasn't really worked, and if they are saying they don't want to see you anyway, its time to just accept that relationship with ILs is over.