More likely initially a 70/30 or 80/20 scenario as that is in the best interest of the child due to the age and breastfeeding.
I would suggest going to a couple therapy. It is a safe environment to have a chance to sit down and going through your issues and talk about it. However, he needs to open to the idea of going there first.
The first year after having a baby is really tough on a couple. My husband and I have been together for 8 years and our relationship has deteriorated a lot the past year after having bub. But these scenarios you are describing are definitely not on, and are extremely disrespectful and should be addressed. Is there someone who can look after bub so that you can spend some time together just you and your partner. Perhaps spending some quality time together just the two of you will spark your relationship backup again? And couples therapy would help a lot too to help him see the way he’s speaking/treating you is unacceptable.
Firstly, I am so sorry you are experiencing this. What you are describing is not okay in an scenario. I am always an advocate on trying to repair a marriage or relationship especially if children are involved. That said, both parties have to be on board and acknowledging that things need to change. I do not want to throw words around but these behaviours you are describing are red flags and potentially emotionally abusive. Do not ignore any gut feelings and your intuition to leave if that is best for you. It is important to understand the parent relationship is modelled to children and for your sake and your baby’s it is important to address these issues or leave. Ask yourself would you want this relationship for your child? It might be worth seeking help as to how best proceed. In terms of splitting custody, due to the very young age and still breast feeding it is unlikely a 50/50 agreement would happen in the early days. These are all things you can get advice on.