Hi.
Us on mumsnet will always do our best to help you - I created a thread myself and it really helped me.
"Threatening to punch me"
"Never to argue with him in public"
"Not to ever tell him what to do with his son"
"Criticises my parenting, saying i am weak & can't cope".
I hope that you are not upset by me highlighting the above words from your post, but i am not sure if you are in a relationship worth carrying on with. These phrases indicate a potentially abusive man, trying to undermine you by calling you weak and undermining you ("can't cope").
The other issue is one of him helping you out.
Can you talk to DP about his behaviour?
If he is resistant to discuss this or cannot see anything wrong regarding threatening to punch you, i would think about alternative places to live and most certainly, ending the relationship.
Forgive me asking, but has he ever punched you? Please do not stay with this man if you do not feel safe with him. Its one thing to have a partner who needs to be prompted to share childcare, but another matter entirely when a partner is controlling.