I can totally understand your feelings about going to stay with your parents if it's a place you don't enjoy being.
However, do think about it more carefully.
If you do split - and I really hope you do - it's going to be a long, complex process before you get to be where you want to be, where you feel you've 'made it out'.
So, take it one step at a time. If you really think that simply being at your parents place for say, three months is going to depress you horribly, then don't do it - but, if you can see it as a step along the road towards getting to where you want to be, then what this could do is sort a LOT of the immediate situation, and most of all allow you to continue to spend maximum time with your DD.
Three months at your parents'. No H in your face. Lots of quality alone time both with your DD and with yourself, sorting out what you want. Crucially, saving money. Probably house-hunting - back in the county you want to be in.
Maybe at least go for a few days, now.
What's making this all muddy in my head is that arguably, I give as good as I get. From my perspective, when he's rude to me, I defend myself. From his perspective that makes us 'as bad as each other.' Maybe he's right and I have no basis to be sanctimonious and harbour thoughts of leaving him? Maybe I need to lead by example for a while (i.e not rise to the bait) and see if he follows suit? If he continues to be obnoxious at least I can say, categorically, that I was the better person.
-none of this matters, really. One of your biggest downfalls will be trying to rationalise things like this, because it will keep you where you are, 'fighting' - which actually translates as staying put and shutting up, because he won't change. The main thing is what it is - you can see what kind of person he is, what life with him is like for you and will be like as a family, and you don't want it. If he wants to disagree and call you all sorts, well fine. Just like his (lucky) ex, you're deciding that you don't want the kind of 'partnership' he's made clear he will create. That's it.
Having recently had babies myself, I would urge you to prioritise, if you can, the time with your DD, because that's the only thing you won't get back, or be able to treat yourself enough to make up for, when you're out of this and through to the other side.