Please. Seriously, please, just pack a few bags and get your sister to pick you up. Like, literally, after you have read this
Please do as Salem suggests. You are too physically and emotionally exhausted to fight this battle alone.
it is easy for people to say - "Just leave him", They may be right, but he is your husband and the father of your precious baby, and you don't want to leave your relationship because you are too fragile in every way at the moment.
What you need is distance - from him and especially his poisonous mother - and the chance to build yourself up; you need physical rest and freedom from drama and aggression. Your parents can give you this space.
Do as others have suggested - get someone to drive you to your mum's - a taxi if necessary. Leave a note saying you felt too unwell to cope alone and have gone for a rest. Don't engage with anyone (including your H) if you don't want to.
He and his family are abusing you just as much as if they slapped you - they know you are unwell and they know you need space, but they won't give you it.
You really need to think of yourself now, otherwise you won't be able to protect your baby from their appalling bullying, either. Also - if you are breast-feeding it will affect your milk production - and what is more, babies pick up on anxiety - it will stress your little one too, even though he doesn't know what is going on.
If you can't fight for yourself, summon your inner Tigress and protect your Cub.