I honestly can't believe you are defending this creep.
We then had a lovely couple if weeks of trying which I ruined last night by saying that I really didn't think I could/will want to return to work in under 2 months after giving birth. Which made him angry. He says I'm throwing money away (meaning potential income).
YOU ruined things? No OP, your husband is ruining your relationship, he is ruining your self-respect and your ability to see clearly. Maternity leave is to help a mother recover from childbirth (which can be traumatic in a variety of ways) and adjust to the raising of a newborn, it's not a flipping holiday, which seems to be what your husband thinks! You will probably find that those two months will be over before you know it, and not many women are in any way ready to work after two months.
You keep defending him, and saying you hope things will get better - it is highly doubtful that things will get better, so don't count on that.
Another thing: he "allowed" you to take out life insurance on him? Bollocks to that, HE should be paying for his own life insurance to protect you and your joint child.
And now you think it's up to his mother to intervene?
It is truly beyond me how you could remotely consider staying with this horrible man. OP please see that how he is treating you is not normal in the slightest, it is abusive. It's as if he has brainwashed you. Certainly he uses his temper to control you.